There is a wide spectrum of available immunotherapies ranging from cytokines such as IL-2 and IFN-α [6], cell-based therapies like vaccines [7] or adoptive cellular therapy to stimulate host’s immune system [8–11], and immune checkpoint blockade strategies using anti-CTLA-4 [12] or anti-PD-1 and anti-PD-L1 antibodies to trigger new immune responses against the tumor. The gene discussed is PDCD1; the disease is neoplasm.