Emerging evidence indicates that mesenteric lymph node NK cells in CRC display elevated expression of T-cell immunoglobulin and mucin domain-3, lymphocyte activation protein-3, PD-1, and T-cell immunoreceptor with immunoglobulin or ITIM domain, accompanied by reduced levels of TNF-related apoptosis-inducing ligand, along with a marked increase in sirtuin 2 expression. Here, PDCD1 is linked to colorectal carcinoma.