PDCD1 and neoplasm: The ability of different tumors to respond to ICB in the case of anti-PD-1/PD-L1 checkpoint immunotherapy is largely determined by the inflammatory state of the tumor microenvironment (10) – while more-inflamed “hot” tumors respond strongly, even in advanced cases, the less-inflamed “cold” tumors respond poorly, or do not respond at all (11).