STO-609 is a specific inhibitor of the Ca2+/Calmodulin-dependent protein kinase kinase(CaM-KK) that inhibits the activities of recombinant CaM-KKα and CaM-KKβ isoforms, with Ki values of 80 and 15 ng/ml, respectively, and also inhibits their autophosphorylation activities. STO-609 inhibits AMPKK activity and inhibits autophagy.