This results in proinflammatory cytokines and ROS, comprising tumor necrosis factor-alpha (TNF-α), IL-1β, IL-12, and IL-23, which aids to the anti-tumor environment.56 We have previously shown that different HuM mouse models respond differently to anti-PD-1.17 Our current study supports a potential immune mechanism behind the potential positive inflammatory response to one dose of anti-PD-1 with an increase in inflammatory (Nos2+) macrophages in the HuM2 mice compared to HuM1 mice. This evidence concerns the gene NOS2 and neoplasm.