PDCD1 and cancer: ICI therapy has shown promising results in various types of cancers, particularly antibodies against the programmed cell death protein 1 (PD-1) T-cell coreceptor and its ligand B7-H1/programmed death-ligand 1 (PD-L1), which have induced durable tumor responses, even in late-stage patients who have failed to respond to multiple classical treatment strategies [47, 48].