HA-100 is a potent protein kinase inhibitor, with IC50s of 4 μM, 8 μM, 12 μM and 240 μM for cGMP-dependent protein kinase (PKG), cAMP-dependent protein kinase (PKA), protein kinase C (PKC) and MLC-kinase, respectively. HA-100 also used as a ROCK inhibitor[1][2].