RKI-1447 inhibits potently ROCK1 and ROCK2 in a dose-dependent manner with IC50 values of 14.5 nM and 6.2 nM, respectively. RKI-1447 suppressed phosphorylation of the ROCK substrates
MLC-2 and MYPT-1 in human cancer cells, but had no effect on the phosphorylation levels of the AKT, MEK, and S6 kinase at concentrations as high as 10 μmol/L.