PDCD1 and neoplasm: Numerous transcripts related to immunological checkpoints, including SIGLEC15, PDCD1LG2 (PD-L2), TIGIT, PDCD1 (PD-1), CD274 (PD-L1), CTLA4, LAG3, and HAVCR2 (TIM3), are integral to tumor immune evasion mechanisms.