Previous studies have attributed four major signalling pathways (MAPK, PI3K/PKB, Wnt/β-catenin and Notch) to the development of resistance against CRC treatment (Li et al., 2011; Corcoran et al., 2012; Xu et al., 2017; He et al., 2018). The gene discussed is PIK3CA; the disease is colorectal carcinoma.