NTHL1 and adenoma: On the other hand, the fact that at least 1⁄4 (7/28) of the reported biallelic mutation carriers who underwent colonoscopy screening had ≤10 adenomas, and that ≥5 hyperplastic polyps were detected in five carriers (polyp number range: 5–>30), lead us to suspect a possible association of NTHL1 mutations with nonpolyposis CRC and serrated/hyperplastic polyposis.