PDK4 and cancer: Although the cellular pyruvate level was not detected by CE-TOFMS and no effect of ACR was found on the phosphorylation of PDHA1 by western blot analysis (Figure 5C), the knockdown of PDK4 expression using RNA interference in JHH7 cells can rescue the decreased cellular ATP levels induced by ACR (Figure 6B), suggesting that PDK4 may be an important feature of ACR's anti-cancer activity.