SMAD4 and colorectal carcinoma: The panel also allowed the identification of mutations in other well-known CRC high-penetrance genes, such as MUTYH (biallelic), APC, SMAD4 and TP53, as well as in moderate-penetrance genes like MUTYH (monoallelic), CHEK2, HNF1A, BRIP1 and XPC. In total, pathogenic or likely pathogenic mutations were found in 18.4% of our cohort, while high-penetrance mutations represented 12.2% of the studied patients.