An allosteric inhibitor of PAK1 (Kd = 7 nM); has an IC50 value of 5.2 nM in a PAK1 dephosphorylation assay; selective for PAK1 over PAK2 (Kd = 400 nM) and over a panel of 442 kinases; inhibits phosphorylation of MEK Ser289 at 6-20 μM but does not inhibit proliferation of Su86.86 cells at concentrations lower than 2 μM