PDCD1 and neoplasm: Type II tumor is known as “hot tumors”[23], characterized by robust T cell infiltration, high PD-L1 expression, elevated TMB, and abundant proinflammatory cytokines [including interferon (IFN)-γ, granzyme B (GrzB), tumor necrosis factor-α (TNF-α), and interleukin-2 (IL-2)][27], rendering them highly sensitive to anti-PD-1/PD-L1 therapy with optimal clinical outcomes.