CAMK4 and autosomal dominant polycystic kidney disease: Treatment of ADPKD cells with an AKT inhibitor (AKTi-1/2) prior to KN-93 did not prevent the effect of KN-93 on P-S6K/S6K, but rather resulted in an additive reduction in P-S6K/S6K, indicating that CaMK4 regulation of mTOR was independent of AKT.