PDCD1 and neoplasm: The interaction between PD-L1 and PD-1 on T cells diminishes T cell function, allowing tumors to evade immune surveillance and contributing to immune evasion.324,325 Additionally, STAT3 induces the production of VEGF,193 promoting angiogenesis and contributing to tumor growth while also having immunosuppressive effects by inhibiting dendritic cell maturation.