Precisely, ≈0.025% or ≈0.09% of mouse hepatocytes expressed POU2F2 at months 5 or 6 when HCC had not been induced, since H&E staining determined normal liver histology with typically distributed and well‐organized cells in the liver (Figure S1D, Supporting Information). The gene discussed is POU2F2; the disease is hepatocellular carcinoma.