SMAD4 and colorectal carcinoma: Molecular studies showed that CRC is under the control of signaling pathways including Wnt/β-catenin, NF-κB, Nrf2,and PI3K/Akt/mTOR, in which KRAS, BRAF, APC, p53, and SMAD-4 possess crucial importance (Zhang et al., 2015; Dawood et al., 2019; Sheng et al., 2019; Wang et al., 2019).