For further analyses, we selected well-known immune checkpoint molecules: PD-1, PD-L1, lymphocyte activating 3 (LAG3), hepatitis A virus cellular receptor 2 (TIM-3), CTLA-4, B and T lymphocyte associated (BTLA), and selectin P ligand (SELPLG), and we found they exhibited opposite prognostic effects in PPRC and PNRC subtypes (Figure 5(b)), implying possible linkage between pyroptosis and checkpoint molecules in different cancer subtypes. Here, PDCD1 is linked to cancer.