United States securities and exchange commission logo

                              May 17, 2021

       Aaron I. Davis
       Chief Executive Officer
       BCTG Acquisition Corp.
       12860 El Camino Real, Suite 300
       San Diego, CA 92130

                                                        Re: BCTG Acquisition
Statement on Form S-4
                                                            Filed April 20,
                                                            File No. 333-255354

       Dear Mr. Davis:

              We have reviewed your registration statement and have the
following comments. In
       some of our comments, we may ask you to provide us with information so
we may better
       understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.

       Registration Statement on Form S-4 filed April 20, 2021

       Questions and Answers About the Proposals
       Q: What interests do BCTG's current officers and directors have in the
Business Combination?,
       page 8

   1.                                                   Please also disclose
that the initial stockholders have agreed to waive their liquidation
                                                        rights with respect to
founder shares and that founder shares will become worthless if you
                                                        fail to complete an
initial business combination within 24 months.
   2.                                                   Please revise the first
bullet point to quantify the out-of-pocket expenses that are owed to
                                                        BCTG's officers,
directors and Sponsor.
 Aaron I. Davis
FirstName  LastNameAaron
BCTG Acquisition  Corp. I. Davis
May        NameBCTG Acquisition Corp.
     17, 2021
May 17,
Page 2 2021 Page 2
FirstName LastName
Q: Will how I vote affect my ability to exercise redemption rights?, page 9

3.       Please also address whether shareholders may exercise their redemption
rights if they
         abstain from voting or fail to vote on the Business Combination
Proposal. Please make
         similar revisions throughout your proxy statement/prospectus where you
         shareholder voting and redemption rights, including on the cover page.
Summary of the Proxy Statement/Prospectus
Parties to the Business Combination, page 14

4.       Please remove the reference on page 16 to "first-in-class" as this
statement implies an
         expectation of regulatory approval and is inappropriate given the
stage of development for
         your programs.
5.       We note your disclosure on page 15 that Tango has established a
sustainable pipeline
         optimized to deliver meaningful clinical benefit to patients. Given
the early stage of
         development, please revise your disclosure to remove any implication
that Tango's
         product candidates will be effective, as determinations of efficacy
are solely within the
         authority of the FDA or comparable regulatory body. Please make
similar revisions to
         your disclosure stating that Tango's development process "[avoids] the
known drawbacks
         of large, empiric clinical trials lacking a patient selection
The Business Combination Proposal, page 17

6.       We note your disclosure stating that one of the factors BCTG   s Board
considered was that
            Tango   s platform is expected to file one new IND every 12 to 18
months.    Please
         expand your disclosure to provide the basis for the Board   s view and
         underlying such view in light of the uncertainty with regard to drug
Conditions to Closing of the Business Combination, page 20

7.       We note your statement that investors should not rely on the
         representations and warranties set forth in the Merger Agreement or
the summaries
         thereof in this proxy statement/prospectus as characterizations of the
actual state of facts
         about BCTG, Sponsor, Tango or any other matter. Please revise to
remove any
         implication that the Merger Agreement and your disclosure of the same
does not
         constitute public disclosure under the federal securities laws.
Risk Factors
Our ability to utilize our net operating loss carryforwards..., page 77

8.       Please revise to clarify whether the proposed business combination
would be considered
         an "ownership change" under the Code and any expected limitations on
your ability to
         utilize NOLs if it is considered an "ownership change." If there is
uncertainty, explain the
         reasons for such uncertainty.
 Aaron I. Davis
FirstName  LastNameAaron
BCTG Acquisition  Corp. I. Davis
May        NameBCTG Acquisition Corp.
     17, 2021
May 17,
Page 3 2021 Page 3
FirstName LastName
New Tango's amended and restated certificate of incorporation will provide that
the Court of
Chancery of the State of Delaware..., page 91

9.       It does not appear that New Tango's Proposed Charter contains a forum
         provision. In addition, your disclosure regarding the forum selection
provision is not
         consistent with either BCTG's current charter or New Tango's Proposed
Bylaws. Please
         revise this risk factor, the risk factor on page 78, and your
description of the Proposed
         Charter on page 262 to identify the correct governing document that
contains the forum
         selection provision you are describing and to ensure consistency
between your disclosure
         and the provision in such governing document. We note also that you
have not included
         the text of Annex B. Please revise to include the relevant text.
Proposal 1 - The Business Combination Transaction
Background of the Business Combination, page 110

10.      Please expand this section to explain why you did not pursue a
transaction with any of the
         35 potential targets with which you engaged in detailed due diligence.
Address in your
         response whether there were any that resulted in a firm offer. In
these instances, disclose
         the initial offer and counter offers.
11.      We note your disclosure that on December 22, 2020, Tango was presented
to the BCTG
         board as one of a few prospective business targets under active
consideration. Please
         describe the selection criteria BCTG used to identify these
prospective targets and why
         you decided to proceed with Tango over other alternatives.
12.      Please expand this section to discuss the following:

                What role did Mr. Davis play in preparing the draft letter of
intent to Tango ? What
              were the material terms of the draft letter of intent ?
                What were the responsibilities of the independent subcommittee
? Please identify the
              members of the independent subcommittee where you discuss the
Board   s decision to
              establish the committee.
                We note that Mr. Davis continued to negotiate with Tango after
the appointment of
              the independent subcommittee. Revise to disclose what
consideration, if any, the
              Board and subcommittee gave to Mr. Davis    conflicts of
                Were there any steps taken other than to establish an
independent subcommittee to
              address potential conflicts of interest?
                Was Mr. Davis involved in the decision to pursue the
transaction and approve the
              terms of the merger as a Tango board member?
                How were the valuation and other material terms of the merger
negotiated from the
              non-binding letter of intent through the execution of the merger
agreement? Revise to
              describe the negotiations in reaching the material terms of the
                Identify the members of BCTG management who met with the
              subcommittee on February 18 and February 22.
 Aaron I. Davis
FirstName  LastNameAaron
BCTG Acquisition  Corp. I. Davis
May        NameBCTG Acquisition Corp.
     17, 2021
May 17,
Page 4 2021 Page 4
FirstName LastName
Engagement of Financial Advisor to BCTG, page 114

13.      We note your disclosure that in developing its opinion, Canaccord
Genuity analyzed
         projected financial and operating data concerning Tango provided to it
by BCTG. Please
         revise to disclose all material projections and underlying
Conditions to the Closing of the Merger, page 121

14.      Please amend your disclosure to identify each condition that is
subject to waiver.
Additional Conditions to Tango's Obligation to Close, page 123

15.      With reference to your disclosure on page 107 that the sponsor will
have the option to
         cover any shortfall through an additional cash investment or
satisfying such shortfall
         through securing investments in BCTG from certain agreed investors in
order to maintain
         a cash balance greater than $300.0 million, please expand your
disclosure to explain
         whether there is a written agreement to this effect and the terms on
which the sponsor or
         other investors will invest additional cash. If there is a written
agreement, please file this
         as an exhibit to your registration statement.
Vote Required for Approval, page 143

16.      We note your disclosure here and on page 88 that as of the date of the
         statement/prospectus, the Sponsor, directors and officers have not
purchased any Public
         Shares. We also note your disclosure on your Form 8-K filed April 14,
2021 that in
         connection with the signing of the merger agreement, a member of the
Sponsor purchased
         800,000 shares of BCTG's common stock from two holders of public
shares at a price of
         $11.00 per share. Please revise your disclosure as appropriate and
specify whether these
         shares are subject to the agreement to vote in favor of the Business
Conflicts of Interest, page 177

17.      With reference to your disclosure on page 179 that related party
transactions require prior
         approval by the audit committee and a majority of uninterested
"independent" directors
         determining that the terms of the transaction are no less favorable to
you than those that
         would be available with respect to such a transaction from
unaffiliated third parties, please
         disclose whether you waived any provisions of that policy and the
reasons therefor. Here
         and under the heading "What interests do BCTG's current directors and
officers have in
         the Business Combination" on page 8, please also disclose the
approximate dollar
         value, when the interest was acquired, and the price paid for the 15%
interest that Boxer
         Capital owns in Tango's outstanding securities.
 Aaron I. Davis
FirstName  LastNameAaron
BCTG Acquisition  Corp. I. Davis
May        NameBCTG Acquisition Corp.
     17, 2021
May 17,
Page 5 2021 Page 5
FirstName LastName
Executive Compensation
Compensation Committee Interlocks and Insider Participation, page 177

18.      With reference to your disclosure on page 176 that your compensation
committee consists
         of Richard Heyman and Carole L. Nuechterlein, please revise this
section to reflect
         whether you currently have a compensation committee.
Information About Tango
Our Pipeline, page 191

19.      Please revise your pipeline table to separate the Phase I and Phase II
columns and to make
         the Phase I, Phase II, and Phase III columns at least as wide as your
Discovery, Lead
         Optimization, and IND-Enabling columns. The pipeline table currently
appears to
         suggest that you have completed more than half of the development
timeline for
20.      We note your inclusion of Target 3, Target 4, and Multiple Targets in
Tango's pipeline
         table. First, please identify any undisclosed product candidates in
the pipeline table.
         Second, to the extent Gilead controls the research on Target 4 such
that you cannot
         provide detailed disclosure about the ongoing studies, please remove
it from the pipeline
         table. Finally, please revise the Multiple Targets row to separately
depict any material
         product candidates or programs individually and provide disclosure in
your prospectus
         regarding these product candidates and programs or remove this row.
Your pipeline table
         should present only programs that are material to your business.
Collaboration and License Agreement with Gilead Sciences, page 209

21.      We note your disclosure on pages 209 and 210 that you are eligible to
receive low double-
         digit tiered royalties on net sales. Please revise your description of
the royalty rate to
         provide a range that does not exceed ten percent.
22.      We note that for those products that you opt to co-develop and
co-promote in the
         United States, you and Gilead will equally split profits and losses
from the sales of such
         products in the United States, you will remain eligible to receive
certain milestone
         payments. Please disclose the aggregate milestone payments you will
remain eligible to
Security Ownership of Certain Beneficial Owners and Management, page 276

23.      To the extent not disclosed, please identify the natural persons who
hold the investment
         and/or voting power of the shares held by the 5% or greater
shareholders identified in your
         table. See Item 403 of Regulation S-K.
 Aaron I. Davis
BCTG Acquisition Corp.
May 17, 2021
Page 6

24.   Please file as exhibits to the registration statement the Gilead
Agreement and the Medivir
      Agreement. See Item 601(b)(10) of Regulation S-K.

25.   Please include a form of proxy card marked as    preliminary    in your
next amendment.
        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration

        You may contact Franklin Wyman at 202-551-3660 or Angela Connell at
if you have questions regarding comments on the financial statements and
matters. Please contact Irene Paik at 202-551-6553 or Christine Westbrook at
with any other questions.

FirstName LastNameAaron I. Davis
                                                           Division of
Corporation Finance
Comapany NameBCTG Acquisition Corp.
                                                           Office of Life
May 17, 2021 Page 6
cc:       Giovanni Caruso - Loeb & Loeb LLP
FirstName LastName