PIK3CA and neoplasm: Somatic mutations in PIK3CA are also common in colon (18–32%), gastric (4–25%), endometrial (36%), liver (36%), brain (27%) and breast (18–40%) tumours (Bachman et al, 2004; Campbell et al, 2004; Samuels et al, 2004; Karakas et al, 2006; Ligresti et al, 2009).