POWER OF ATTORNEY 	Know all by these presents, that the undersigned hereby constitutes and appoints the Chief Financial Officer of Oncternal Therapeutics, Inc., a Delaware corporation (the "Company"), who is currently Richard Vincent, and the General Counsel of the Company, who is currently Chase Leavitt, and their respective successors, signing singly, the undersigneds true and lawful attorney-in-fact to: (1) prepare, execute in the undersigneds name and on the undersigneds behalf, and submit to the U.S. Securities and Exchange Commission (the "SEC") a Form ID, including amendments thereto, and any other documents necessary or appropriate to obtain codes and passwords enabling the undersigned to make electronic filings with the SEC of reports required by Section 16(a) of the Securities Exchange Act of 1934 and the rules thereunder (the "Exchange Act") or any rule or regulation of the SEC; (2)	execute for and on behalf of the undersigned, in the undersigneds capacity as an officer and/or director of the Company and/or beneficial owner of more than 10% of the Companys capital stock, Forms 3, 4, and 5 and any amendments thereto in accordance with Section 16(a) of the Exchange Act; (3) do and perform any and all acts for and on behalf of the undersigned which may be necessary or desirable to complete and execute any such Form 3, 4, or 5, complete and execute any amendment or amendments thereto, and timely file such form with the SEC and any stock exchange or similar authority; and (4) take any other action of any type whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required by, the undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such attorney-in-facts discretion. 	The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-facts substitute or substitutes, shall lawfully do or cause to be done by virtue of this Power of Attorney and the rights and powers herein granted. 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 undersigneds responsibilities to comply with Section 16 of the Exchange Act. 	The undersigned agrees that each such attorney-in-fact herein may rely entirely on information furnished orally or in writing by the undersigned to such attorney-in-fact. The undersigned also agrees to indemnify and hold harmless the Company and each such attorney-in-fact against an losses, claims, damages or liabilities (or actions in these reports) that arise out of or are based upon any untrue statements or omission of necessary facts in the information provided by the undersigned to such attorney-in-fact for purposes of executing, acknowledging, delivering or filing Forms 3, 4 or 5 (including amendments thereto) or Form ID and agrees to reimburse the Company and such attorney-in-fact for any legal or other expenses reasonably incurred in connection with investigating or defending against any such loss, claim, damage, liability or action. 	This Power of Attorney supersedes any power of attorney previously executed by the undersigned regarding the purposes outlined in the first paragraph hereof ("Prior Powers of Attorney"), and the authority of the attorney-in-fact named in any Prior Powers of Attorney is hereby revoked. 	This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file Forms 3, 4, and 5 with respect to the undersigneds holdings of and transactions in securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing attorneys-in-fact. 	IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 25th day of May, 2021. /s/ Daniel L. Kisner, MD Name: Daniel L. Kisner, MD