Company: IOBT
Filing Date: 2025-05-23
Form Type: S-3
Source: 0001193125-25-125831
Chunk: 29

Company: IO Biotech, Inc.
Filing Date: 2025-05-23
Form: S-3
Chunk 29
---
 to believe that it meets all of the requirements for filing on Form S-3and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Copenhagen, Denmark on May 23, 2025.

| IO BIOTECH, INC. |     |                                       |
| By:              |     | /s/ Mai-Britt Zocca                   |
|                  |     | Mai-Britt Zocca, Ph.D.                |
|                  |     | President and Chief Executive Officer |

II-5

POWER OF ATTORNEY We, the undersigned directors and officers of IO Biotech, Inc. (the Company), hereby severally constitute and appoint Mai-BrittZocca and Amy Sullivan, and each of them singly, our true and lawful attorneys, with full power to them, and to each of them singly, to sign for us and in our names in the capacities indicated below, the registration statement on Form S-3filed herewith, and any and all pre-effectiveand post-effective amendments to said registration statement, and any registration statement filed pursuant to Rule 415 under the Securities Act of 1933, as amended, in connection with the registration under the Securities Act of 1933, as amended, of equity securities of the Company, and to file or cause to be filed the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as each of them might or could do in person, and hereby ratifying and confirming all that said attorneys, and each of them, or their substitute or substitutes, shall do or cause to be done by virtue of this Power of Attorney. This Power of Attorney does not revoke any power of attorney previously granted by the undersigned, or any of them. Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed by the following persons in the capacities indicated on the date indicated:

| Signature                     
 /s/ Mai-Britt Zocca           |     | Title                                                
 President and Chief Executive Officer                
 (Principal Executive Officer)                        |     | Date         
 May 23, 2025 |
|:------------------------------|:----|:-----------------------------------------------------|:----|:-------------|
| Mai-Britt