PDCD1 and neoplasm: Interfering with the PD-1 (programmed cell death protein 1) and CTLA-4 (cytotoxic T-lymphocyte-associated antigen 4) immune checkpoints has been routinely used in tumor immunotherapy, although, as a recently discovered immune checkpoint in tumor immunotherapy, an increasing number of studies have focused on the role of CD276 (B7-H3) [2].