PAK1 and cardiac hypertrophy: Furthermore, application of FTY720 (a synthetic analog structurally similar to sphingosine) induced Pak1 activation and restrained the development of cardiac hypertrophy wild-type mice stressed by a pressure overload, but not in Pak1cko mice, suggesting the anti-hypertrophic effect of FTY720 was likely due to its function on activation of Pak1 [6].