TGFB1 and colorectal carcinoma: Pittman et al. [11] reported that a C to G SNP at 44,703,563 bp, a SNP in strong linkage disequilibrium with other genetic variations around 18q21, may be the functional variant responsible for 18q21-associated variations in CRC risk through differential SMAD7 expression and subsequent TGF-β signaling.