Next, we checked effects of NAMPT inhibition on normal cholangiocytes, NHC, and CCA cell growth and found that FK866, a specific inhibitor of NAMPT, decreased CCA cell (HuCCT1, KMCH, and EGI) growth in a concentration (1–20 nM)-dependent manner, while minimally affecting normal cells (Figure 2A–D). Here, NAMPT is linked to cholangiocarcinoma.