RPS6KB1 and autosomal dominant polycystic kidney disease: KN-93 treatment for 24 h decreased P-S6K/S6K and P-S6/S6 in a dose-dependent manner in ADPKD cells (Figure 3A–C), with 10 μM KN-93, the highest concentration tested, reducing P-S6K/S6K and P-S6/S6 levels by 81% and 86%, respectively.