SMAD4 and colorectal carcinoma: The most frequent aberrations found in CRC patients are mutations in adenomatous polyposis coli (APC), catenin-β1 (CTNNB1), family with sequence similarity 123B (FAM123B; also known as AMER1), kirsten rat sarcoma viral oncogene homolog (KRAS), B-Raf proto-oncogene, serine/threonine kinase (BRAF), erb-b2 receptor tyrosine kinase 2 E (RBB2), SMAD family member 4 (SMAD4), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit-α (PIK3CA), transforming growth factor-β receptor 2 (TGFBR2), AT-rich interactive domain 1A (ARID1A), and tumor Protein P53 (TP53).