Immune checkpoint inhibitors, such as drugs targeting PD-1, PD-L1, and CTLA-4, block the immune evasion mechanisms of tumor cells, thereby enhancing the anti-tumor activity of immune cells.84,603–606 Additionally, technologies like adoptive cell transfer immunotherapy offer a variety of treatment options.607 Despite these advancements, resistance to immunotherapy has emerged as a significant focus of contemporary research. Here, CTLA4 is linked to neoplasm.