Moon et al. [21] reported the development of hepatic steatosis and female reproductive problems in adult mice after ELOVL5 knockout, which led to elevated levels of hepatic triacylglycerols due to increased activities of sterol regulatory element-binding protein (SREBP)-1c and products of their target genes, such as insulin-sensitive glucose transporter type 4 and acetylcholine. The gene discussed is SREBF1; the disease is fatty liver disease.