STAT3 and neoplasm: Additionally, the stimulation of the JAK/STAT3 signaling cascade exhibits strong links to PD-L1 expression: blocking JAK/STAT3 activation not only markedly diminishes the effects of M1-like tumor-associated macrophages on OSCC cell colony formation, invasion, migration, microsphere formation, and xenograft development [66] but also inhibits PD-L1 expression on M1 macrophages, promoting their polarization and enhancing proinflammatory cytokine production [67].