FRAX486 is a selective inhibitor of group I PAKs with IC50s of 8.25/39.5, /55.3 nM for PAK1/PAK2/PAK3 respectivelt and less potent for PAK4 (IC50=779 nM).

FRAX597, a small-molecule pyridopyrimidinone, is a potent and ATP competitive inhibitor of the group I PAKs (PAK1 IC50= 8 nM, PAK2 IC50= 13 nM, PAK3 IC50= 19 nM).

PF-3758309 is an inhbitor of PAKs with IC50 of 1.3 nM for PAK4, which inhbits tumor growth in HCT116, A549, M24met and other xenograft tumor models.