Different causes and mechanisms have been postulated for chemoresistance in CRC, e.g. via signaling pathways like NFKB, Wnt/ β-catenin, and PI3K/AKT which lead to ABC transporters overexpression or the overexpression of Thymidylate synthase and FOXO1 proteins in CRC [3, 6]. The gene discussed is TYMS; the disease is colorectal carcinoma.