PI5KI isoform silencing does not impair receptor-triggered PI3K activity. (A) Uninfected, shRNA-ctr, shRNA-PI5KIα, or shRNA-PI5KIγ NK92 populations were stimulated with anti-2B4 mAb for the indicated times. Akt phosphorylation status was evaluated by immunoblot analysis with anti-phospho Akt (anti-pAKT) Ab. The same membranes were reprobed with anti-total Akt (anti-AKT) Ab for sample normalization. One representative experiment is shown. (B) Data were quantified by densitometric analysis. Phospho-Akt was normalized for the respective total Akt levels. Data are expressed as arbitrary units (mean ± SD) of 5 separate experiments. The difference obtained between the groups is not significant.