PAK1 and schwannoma: FRAX597, a noted potent PAK1 inhibitor with an IC50 value of 7.7 nM, displayed a selectivity of PAK1 over PAK4 of > 130-fold, which presented a potent antiproliferatory capacity against NF2-deficient schwannoma cells and significant anti-tumor activity in an orthotopic model of NF2 186.