CTLA4 and cancer: In recent years, the targeting of ICIs such as PD‐1, PD‐L1, and CTLA4 has emerged as a crucial approach in tumor treatment.[25] αPD‐1 can competitively bind to PD‐1 on the surface of T cells with PD‐L1 of cancer cells, thereby enhancing the ability of T cells to kill cancer cells.