FIIN-1 is a potent, irreversible, selective FGFR inhibitor. FIIN-1 binds to FGFR1/2/3/4 and Flt1/4 with Kds of 2.8/6.9/5.4/120 nM and 32/120 nM respectively. The biochemical IC50s of FIIN-1 are 9.2, 6.2, 11.9, and 189 nM against FGFR1/2/3/4, respectively[1].