PDCD1 and neoplasm: Under hypoxic conditions, HIF-1α expressioncan be amplified,triggering a cascade of signaling events that activate the PD-1/PD-L1immune checkpoint pathways, ultimately leading to diminished immunogenicity,enhanced tumor cell immune evasion and compromised efficacy of cancerimmunotherapy. Consistent with this observation,hypoxic conditions extensively induced the mRNA and protein expressionof hypoxia-related genes, such as HIF1A and PD-L1,which could be effectively alleviated by the NP1192 treatment (Figure A–D).