However, some researchers suggest that there is no association between increased cancer risk and the APEX Asp148Glu polymorphisms [20] or even that its occurrence decreases the risk—Brevik et al. report that carriers of the APEX codon 51 Gln/His genotype had a reduced CRC risk compared with carriers of the Gln/Gln genotype [30]. This evidence concerns the gene APEX1 and colorectal carcinoma.