As a type of immunodeficient mice, NOD/Shi‐scid/Il2r–/– (NOG) mouse is commonly used for analyzing in vivo tumorigenic abilities of tumor cells.[20] Surprisingly, POU2F2+ hepatocytes could form xenograft tumors in NOG mice before they acquired stemness, demonstrating that POU2F2+ hepatocytes may be the cells of origin for HCC. The gene discussed is POU2F2; the disease is hepatocellular carcinoma.