TGFB1 and colorectal carcinoma: We found a significant association between the mutant statuses of the SMAD4 gene with that of the KRAS gene, thereby suggesting that similar mechanisms in our population where a cross talk between the MAP Kinase and TGF-β pathways might play a role in the development of CRC to advanced stage cumulatively [38,39,43] as we found 29 (60.4%) of higher grade tumors (C+D) were mutants for either of the two genes (KRAS and SMAD4) [Table 5].