Immune checkpoint inhibitor (ICI) immunotherapy targeting programmed cell death 1 (PD-1) or its ligand, PD-1 ligand 1 (PD-L1), also exhibits restricted efficacy in advanced PDAC on account of its immunologically "cold" tumor profile, characterized by a low mutation burden and diminished expression of CD8, PD-1, and PD-L1 [6–8]. This evidence concerns the gene PDCD1 and neoplasm.