First, AFP expression level was assessed in various types of cells and categorized into AFP-positive HCC cells (Huh7, HepG2, and Hep3B), AFP-negative HCC cells (HepI), non-HCC cancer cells (U343 and A549), normal fibroblasts (BJ, WI38, and IMR90), and primary human hepatocytes (HEP-187M) (Fig. 1B). Here, AFP is linked to hepatocellular carcinoma.