MTOR and cancer: The 5-HT-induced invasion of MDA-MB-231 cancer cells was blocked by inhibitors of Src (AZM-475271), PI3K (wortmannin), Akt (tricirbine), MAPKK (U0126), or ERK (PD98059) (Fig. 3d), but interestingly, not by inhibitors of mTOR (rapamycin) or p38 (SB203580) (Fig. 3d), indicating that not all activated Gβγ signaling molecules were involved in the 5-HT-induced invasion.