IL6 and cancer: Moreover, other inflammatory cytokines also participated in the induction of mRNA expression of PD-L1, including TGF-β, TNF-α, and IL-6 (66, 73–75), and these cytokines are also important participators in the lymph node metastases, which may also serve as alternative pathways for the upregulation of PD-L1 in cancer cells and train them to become more powerful metastatic cancer cells for further dissemination in other organs.