Docking of KPT-9274 into NAMPT. (A) Two lowest energy docked conformers of KPT-9274 (gray) overlaid on FK866 (blue) showing consistent binding mode with alternate binding modes for the piperidine end of KPT-9274. (B) NAMPT homodimer shown using surface representation, chain A (white) depicted at binding cavity with KPT-9274 (gray) and FK866 (blue) complexed to chain B (purple). (C) Detailed view of distal tunnel containing bound inhibitors showing favorable ring-stacking interaction between FK866 and tyrosine residue of chain B compared with the steric clash of KPT-9274 with the same tyrosine.