PIK3CA and neoplasm: In CRC, mutations of BRAF and PI3K genes are detected in ∼5–10% and 6–13% of the tumours, respectively (Moroni et al, 2005; Lièvre et al, 2006; Di Nicolantonio et al, 2008; Laurent-Puig et al, 2009; Prenen et al, 2009; Sartore-Bianchi et al, 2009).