KN-62 is a selective and reversible inhibitor of calmodulin-dependent protein kinase II (CaMK-II) with a Ki of 0.9 μM for rat brain CaMK-II. KN-62 directly binds to the calmodulin binding site of CaMK-II. KN-62 displays noncompetitive antagonism at P2X7 receptors in HEK293 cells, with an IC50 value of approximately 15 nM.