Injection of AAV8-TBG-Hnf4a by superficial temporal vein on day two after birth successfully overexpressed Hnf4a in the liver (Supplementary Fig. 7m) and alleviated liver damage caused by hepatic Mettl3 knockout compared to AAV8-Ctrl at two weeks, evidenced by an increased number of Ki67+ proliferating hepatocytes and reduced hepatic steatosis (Fig. 6k-m). The gene discussed is HNF4A; the disease is steatosis.