Of these, PIK3CA and associated kinases - as key regulators of the PI3K/AKT pathway - are highly attractive predictive and, in fact, also potentially actionable candidates: PIK3CA is a proto-oncogene encoding phosphatidylinositol 3-kinase (PI3K), the signal inducer of the PI3K-AKT pathway and is mutated in about 10-30% of CRC, mostly in sequence hotspots in exons 9 and 20 [7, 8]. The gene discussed is PIK3CA; the disease is colorectal carcinoma.