SMAD4 and colorectal cancer: Of the 29 patients recruited in this study, one or more somatic mutations in the 8 colorectal cancer-related genes (KRAS, TP53, APC, PIK3CA, SMAD4, FBXW7, NRAS, and MAP2K1) were detected in 26 (89.7%) patients with mCRC, while no mutations in the remaining 6 genes (AKT1, BRAF, CTNNB1, EGFR, ERBB2, and GNAS) were detected.