In a diethylnitrosamine (DEN) / carbon tetrachloride (CCl4)-induced HCC mouse model, Fxyd5-knockout (KO) mice (Fxyd5−/−) developed fewer and smaller tumors, with significantly lower tumor incidence at 19 weeks, than wild-type controls did (Fig. 1k–o and Supplementary Fig. 1i–k). The gene discussed is FXYD5; the disease is neoplasm.