United States securities and exchange commission logo

                          August 31, 2022

       Katherine Stueland
       Chief Executive Officer
       Sema4 Holdings Corp.
       333 Ludlow Street, North Tower, 8th Floor
       Stamford, Connecticut 06902

                                                        Re: Sema4 Holdings
Statement on Form S-3
                                                            Filed August 26,
                                                            File No. 333-267108

       Dear Ms. Stueland:

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

               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 Margaret
Schwartz at 202-551-7153 with any questions.


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Per Chilstrom, Esq.