To investigate the role of MBD4 in tumorigenesis and the interaction between MBD4 and MMR genes, sequence analysis of the entire coding region of MBD4 was performed in a total of 332 CRC cases, including 259 hereditary (i.e., meeting the Amsterdam/Bethesda criteria) or familial cases (partially fulfilling the Amsterdam/Bethesda criteria) and 73 sporadic cases. Here, MBD4 is linked to colorectal carcinoma.