Lipton et al. did not find any SMAD4 mutations in MAP CRCs, but did find 18q LOH at the same frequency as in sporadic CRCs.[11] Recently we reported that the chromosome 18q LOH in MAP carcinomas mainly comprises copy neutral LOH and not physical loss, as observed in sporadic CRC.[13]. Here, SMAD4 is linked to mutyh-associated polyposis.