TNF and renal cell carcinoma: Another proposed mechanism is that RCC inhibits the host antitumor immune response by promoting PGE2 production by PBMC and a shift of the cytokine profile in favor of a Th2 response [142], or that RCC cells induce PGE2, IL-10, and TNF-α production by monocytes, which down-regulate the expression of the cell surface molecules involved in antigen presentation, as well as their endocytic capacity [143].