SMAD4 and colorectal carcinoma: According to the sequencing analysis of SMAD4, SMAD2 and SMAD3 in a group of 744 primary CRC patients and 36 CRC cell lines, the prevalence of SMAD4, SMAD2 and SMAD3 mutations was found to be 8.6%, 3.4% and 4.3% in sporadic CRC, respectively.