The c-MET–selective inhibitor PF-2341066 induces dose-dependent apoptosis for KSHV⁺ PEL cells. (A-B) A total of 4 PEL cell lines were incubated with the indicated concentrations of PF-2341066 for 24 hours, then cell apoptosis was quantified by Annexin V–PI/flow cytometry. BCBL-1 was shown as an example for the cell subpopulation diagram in panel A. (C) The HGF concentrations in supernatant were determined by ELISA. Error bars represent the S.E.M. for 3 independent experiments. *P < .01. (D) The protein expression in BCBL-1 was measured by immunoblots.