HGF and plasma cell myeloma: To further confirm the cytotoxic effects of amuvatinib in myeloma cells is associated with inhibiting the HGF/MET signaling axis, we compared the efficacy of amuvatinib to induce apoptosis in U266 cells versus RPMI-8226/S, a myeloma cell line which express 75% lower levels of HGF and 95% lower levels of MET (Additional file1: Figure S1).