These types are (1) hepatocyte nuclear factor-1α (HNF-1α)-mutated HCAs (H-HCA), (2) β-catenin-mutated HCAs (b-HCA), (3) inflammatory HCAs (I-HCA) (which harbor mutations involving the interleukin-6 signal transducer), and (4) unclassified. The gene discussed is HNF1A; the disease is hepatocellular adenoma.