IL17A and colorectal carcinoma: TNF-α, IL-6, IL-10, and IL-1β also have been shown to induce PD-L1.10 IL-17A is a new player in the CRC cytokine milieu, which is associated with tumorigenesis, angiogenesis, and metastasis of CRC.16 Several lines of evidence suggest that IL-17A can increase the expression of PD-L1 and promote tumor progression in HCC or ovarian cancer.46 47 Nevertheless, the detailed mechanism was not established.