Recently, a multivariate analysis revealed that in CRC, high tumor PD-L2 expression was correlated with a weak Crohn's-like lymphoid reaction, which was deemed to play a significant role in adaptive immune responses against tumors, suggesting that PD-L2 expression might reduce Crohn's-like lymphoid reactions to suppress antitumor immunity (41). This evidence concerns the gene PDCD1LG2 and colorectal carcinoma.