He was referred to genetic counseling, and an analysis of a colorectal cancer gene panel consisting of 17 genes was performed (APC, BMPR1A, CDH1, EPCAM, GREM1, MLH1, MSH2, MSH6, MUTYH, NTHL1, PMS2, POLD1, POLE, PTEN, SMAD4, STK11, TP53). The gene discussed is NTHL1; the disease is colorectal cancer.