144 0001757770 XXXXXXXX LIVE 0001653087 Alector, Inc. 001-38792 131 Oyster Point Blvd. Suite 600 South San Francisco CA 94080 (415)-231-5660 Arnon Rosenthal Officer Director Common Stock E*TRADE Financial Corporation

3 Edison Drive Alpharetta GA 30005

5102 34847 83351778 06/02/2023 Nasdaq Common Stock 06/01/2023 Vesting of Restricted Stock Units Issuer N 14930 06/01/2023 (1) N Arnon Rosenthal

C/O Alector, Inc. 131 Oyster Point Blvd., Suite 600 South San Francisco CA 94080

Common Stock 03/17/2023 15186 94428 Arnon Rosenthal

C/O Alector, Inc. 131 Oyster Point Blvd., Suite 600 South San Francisco CA 94080

Common Stock 03/02/2023 5849 48651 (1) The securities to be sold were received upon the settlement of vested restricted stock units. 06/01/2023 /s/ Jordan Hochstrasser, by power of attorney alec-ex24.htm EX-24 EX-24 <html>
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  <p style="text-indent:0.0%;font-size:10.0pt;margin-top:0.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:right;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:bold;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">Exhibit 24</font></p>
  <p style="text-indent:0.0%;font-size:10.0pt;margin-top:0.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:center;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:bold;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">POWER OF ATTORNEY</font></p>
  <p style="text-indent:6.667%;font-size:10.0pt;margin-top:18.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">The undersigned reporting person of Alector, Inc., (the &#x201c;Company&#x201d;) hereby constitutes and appoints Arnon Rosenthal, Marc Grasso, Cameron Hagen and Jordan Hochstrasser, and each of them, the undersigned&#x2019;s true and lawful attorney-in-fact to:</font><font style="color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;"> </font></p>
  <p style="margin-left:6.667%;text-indent:-7.143%;padding-left:6.667%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">1.	complete and execute Form 144, Notice of Proposed Sale of Securities, and any other required form, and all amendments to such forms, as such attorney-in-fact shall in his or her discretion determine to be required or advisable pursuant to the Securities Exchange Act of 1933 and the rules and regulations thereunder, or any successor laws and regulations, as a consequence of the undersigned&#x2019;s disposition of securities of the Company; and</font></p>
  <p style="margin-left:6.667%;text-indent:-7.143%;padding-left:6.667%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">2.	do all acts necessary in order to file such forms with the Securities and Exchange Commission, any securities exchange or national association, the Company and such other person or agency as the attorneys-in-fact shall deem appropriate.</font></p>
  <p style="text-indent:6.667%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">The undersigned hereby ratifies and confirms all that said attorneys&#x2011;in-fact and agents shall do or cause to be done by virtue hereof.  The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not assuming, nor is the Company assuming, any of the undersigned&#x2019;s responsibilities to comply with Rule 144 of the Securities Exchange Act of 1933 (as amended).<br></font><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">&#160;</font></p>
  <p style="text-indent:6.667%;font-size:10.0pt;margin-top:0.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file Form 144 with respect to the undersigned&#x2019;s disposition of securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the Company and the foregoing attorneys-in-fact.</font><font style="color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;"> </font></p>
  <p style="text-indent:6.667%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 30th day of May, 2023.</font></p>
  <p style="text-indent:0.0%;font-size:10.0pt;margin-top:0.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="white-space:pre-wrap;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">&#160;</font></p>
  <p style="margin-left:46.667%;text-indent:0.0%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">Signature: </font><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;text-decoration:underline;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;"> /s/ Arnon Rosenthal	</font></p>
  <p style="margin-left:46.667%;text-indent:0.0%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:justify;"><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">Print Name: </font><font style="background-color:rgba(0,0,0,0);color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;text-decoration:underline;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">  Arnon Rosenthal</font><font style="color:rgba(0,0,0,1);white-space:pre-wrap;font-weight:normal;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">	   </font></p>
  <p style="text-indent:0.0%;font-size:10.0pt;margin-top:12.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:left;"><font style="white-space:pre-wrap;font-size:10.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">&#160;</font></p>
  <p style="text-indent:0.0%;font-size:10.0pt;margin-top:0.0pt;font-family:Times New Roman;margin-bottom:0.0pt;text-align:left;"><font style="white-space:pre-wrap;font-size:12.0pt;font-family:&quot;Times New Roman&quot;, serif;min-width:fit-content;">&#160;</font></p>
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