GSK180736A (GSK180736), developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2(G protein-coupled receptor kinase 2) with logIC50 pf -6.6 (logIC50 -4.0 for GRK5 and >-3 for GRK1); ≥400-fold selective for GRK2 over both GRK1 and GRK5.