CTLA4 and neoplasm: In phase 3 clinical trials, the targeting and blocking of the PD-1/PD-L1 and CTLA-4 immune evasion pathways in tumor cells effectively reverses T cell exhaustion, alleviates T cell activation inhibition, and ultimately results in a significant prolongation of progression-free survival as well as an enhancement of tumor response rates, demonstrating notable antitumor effects (174, 175).