United States securities and exchange commission logo





                            June 30, 2021

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

                                                        Re: BCTG Acquisition
Corp.
                                                            Amendment No. 1 to
Registration Statement on Form S-4
                                                            Filed June 17, 2021
                                                            File No. 333-255354

       Dear Mr. Davis:

             We have reviewed your amended 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
       response.

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.
Unless we note
       otherwise, our references to prior comments are to comments in our
[Month day, year] letter.

       Amendment No. 1 to Registration Statement on Form S-4

       Parties to the Business Combination
       Tango, page 16

   1.                                                   We note your response
to prior comment 5 and your statement that in vitro and in
                                                        vivo preclinical data
for USP1 "demonstrated potent anti-tumor activity and suggests this
                                                        molecule will have the
potential to be effective as a single agent in PARP-naive and
                                                        PARP-resistant cancers
with a BRCA1 mutation." Please revise this disclosure and similar
                                                        statements that imply
that your product candidates are effective or are likely to be
                                                        approved. You may
present objective data resulting from your preclinical testing without
                                                        concluding efficacy.
 Aaron I. Davis
BCTG Acquisition Corp.
June 30, 2021
Page 2
Proposal 1 - The Business Combination Proposal
Background of the Business Combination, page 114

2.    We note your revisions in response to comment 12 and re-issue in part.
Please identify
      the members of BCTG management who met with the independent subcommittee
on
      February 18 and February 22.
Information About Tango, page 194

3.    We note your revisions to the pipeline table in response to our prior
comment 19 and re-
      issue in part. Please separate the Phase I and Phase II columns in the
pipeline tables on
      pages 17 and 196 or tell us the basis for your belief that you will be
able to conduct Phase
      I/II trials for all your product candidates. In addition, please explain
what is involved in
      "lead-optimization" and why you believe this is a separate and distinct
development
      phase, as opposed to part of discovery and/or IND-enabling studies, or
revise.
Comparison of Corporate Governance and Stockholder Rights
Choice of Forum, page 277

4.    We note your revisions in response to prior comment 9. Please also revise
the "Exclusive
      forum for certain lawsuits" section on page 270 to refer to BCTG's
current charter and the
      "Choice of Forum" section on page 277 to describe the forum selection
provision in the
      Proposed Bylaws.
        You may contact Franklin Wyman at 202-551-3660 or Angela Connell at
202-551-
3426 if you have questions regarding comments on the financial statements and
related
matters. Please contact Irene Paik at 202-551-6553 or Christine Westbrook at
202-551-
5019 with any other questions.



                                                            Sincerely,
FirstName LastNameAaron I. Davis
                                                            Division of
Corporation Finance
Comapany NameBCTG Acquisition Corp.
                                                            Office of Life
Sciences
June 30, 2021 Page 2
cc:       Giovanni Caruso - Loeb & Loeb LLP
FirstName LastName