The WNT (Vermeulen et al., 2010), PI3K (Tenbaum et al., 2012), BMP/TGF‐beta (Lombardo et al., 2011) signalling pathways all affect self‐renewal and differentiation capacity of CRC stem cells, and thus, mutations in these pathways likely regulate the frequency of CRC‐SCs. Here, PIK3CA is linked to colorectal carcinoma.