KN-93 is an inhibitor of calmodulin-dependent kinase II (CaMKII); it may also inhibit L-type Ca2+ channels. KN-93 exhibits anticancer, anti-arrhythmic, cardiomodulatory, antinociceptive, and immunomodulatory activities. In vitro, KN-93 decreases VEGF expression. When combined with VEGF inhibitors, this compound decreases tumor growth in animal models of cancer. In other animal models, KN-93 prevents the development of arrhythmia and increases levels of Treg cells. KN-93 also increases withdrawal latency in animal models of thermal and mechanical pain.