PIK3CB and cervical cancer: To determine whether cervical cancer cells bearing the PIK3CA-E545K mutation also displayed enhanced PI3K signaling, A5-WT, A5-E545K and HeLa-E545K cells were grown under reduced serum conditions and AKT phosphorylation was assessed by immunoblotting with a phosphospecific antibody against the mTORC2 phosphorylation site Akt-S473.