Additionally to downregulate major histocompatibility complex (MHC) class I on the tumor cells' surface and inactivation of the antigen-processing machinery, upregulation of immune-checkpoint-molecules (such as programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1(PD-L1)) represents another escape mechanism [4]. The gene discussed is PDCD1; the disease is neoplasm.