We analyzed the expression of immune checkpoint (IC) molecules (IDO, TIM-3, LAG-3, CTLA-4 (CD152), PD-1, PD-L1, PD-L2, B7-H3, B7-H4, B7-H5, and TIGIT) to provide a theoretical basis for tumor immunotherapy. Here, CTLA4 is linked to neoplasm.