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                          April 5, 2024

       Andrew Robbins
       Chief Executive Officer
       Cogent Biosciences, Inc.
       275 Wyman Street, 3rd Floor
       Waltham, MA 02451

                                                        Re: Cogent Biosciences, 
Inc.
                                                            Registration 
Statement on Form S-3
                                                            Filed March 29, 
2024
                                                            File No. 333-278382

       Dear Andrew Robbins:

              This is to advise you that we have not reviewed and will not 
review your registration
       statement.

               Please refer to Rules 460 and 461 regarding requests for 
acceleration. 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.

                                                        Please contact Doris 
Stacey Gama at 202-551-3188 with any questions.



                                                                                
                          Sincerely,

                                                                                
                          Division of Corporation Finance
                                                                                
                          Office of Life Sciences
       cc:                                              Ryan Murr, Esq.