SU16f is a potent and selective PDGFRβ inhibitor with IC50s of 10 nM, 140 nM, 2.29 μM for PDGFRβ, VEGF-R2, FGF-R1, respectively[1]. Neutralization of PDGFRβ receptor by SU16f blocks the promoting role of GC-MSCs (gastric cancer-derived mesenchymal stem cells) conditioned medium in gastric cancer cell proliferation and migration[2].