KRAS and lung cancer: However, it is likely that PI3K might act in concert with other oncogenic hits to promote malignant transformation of lung epithelial cells since several NSCLCs present aberrant expression of AKT1, AKT2 or loss of PTEN in addition to PIK3CA overexpression (7%, 10% and 21%, respectively) and PIK3CA mutations are not mutually exclusive with EGFR and KRAS mutations in lung cancer [49]–[51], [54].