Based on these studies of C/EBPα‐p300 complexes and data of ChIP assay, we conclude that the C/EBPα‐p300 complexes are not accumulated in old KO mice and that this leads to the lack of activation of the DGAT1 promoter and prevention of hepatic steatosis associated with aging. The gene discussed is CEBPA; the disease is Hepatic steatosis.