tokens: The Ras inhibitor ( GW5074 ; 1 . 0 micro M ) , Raf inhibitor ( lovastatin ; 1 . 0 micro M ) , MEK1 / 2 inhibitor ( SL327 ; 1 . 0 micro M ) , and MAPK inhibitor ( PD98059 ; 1 . 0 micro M ) significantly blocked the potentiation of NGF - induced neurite outgrowth by SA4503 ( 1 . 0 micro M ) ( Figure 7 ) .