United States securities and exchange commission logo March 7, 2023 Arnon Rosenthal, Ph.D. Chief Executive Officer Alector, Inc. 131 Oyster Point Blvd., Suite 600 South San Francisco, CA 94080 Re: Alector, Inc. Registration Statement on Form S-3 Filed February 28, 2023 File No. 333-270126 Dear Arnon Rosenthal: 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 Jason Drory at 202-551-8342 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Michael Coke