Our data suggest that inactivation of the NTHL1 wild-type allele is a rare event in colorectal tumors, which is in agreement with the observation that loss of heterozygosity of chromosome arm 16p is not frequently observed in CRC.8 We were unable to discriminate between individuals with polyposis or CRC due to the historical nature of the case collections. This evidence concerns the gene NTHL1 and colorectal carcinoma.