CTLA4 and neoplasm: Currently, immune checkpoint inhibitors (anti-PD-1, and anti-PD-L1, anti-CTLA-4 antibodies), chimeric antigen receptor T (CAR-T) cell therapies and anti-tumor vaccines constitute the main immunotherapy strategies, which have been able to result in certain therapeutic effects and durable clinical responses in a subset of tumor types and patients [4–6].