TNF and colorectal carcinoma: Impaired regulation of serum levels of proinflammatory cytokines, such as Transforming Growth Factor β (TGF-β) and Tumor Necrosis Factor Alpha (TNF-α), and the down-expression of Peroxisome Proliferator Activated Receptor Gamma (PPAR-γ), known to be a growth-limiting and differentiation-promoting factor, are major signaling pathways involved in the pathogenesis of CRC [13,14].