Hasan KM, et al. - In this analysis, investigators examined the harmful effects of electronic nicotine delivery systems (ENDS), also known as e-cigarettes, on the liver. Apolipoprotein E null (ApoE-/-) mice on a Western diet( WD) have been exposed to saline or ENDS with 2.4% nicotine aerosol for 12 weeks using the newly developed mouse ENDS exposure model system that delivers nicotine to mice that results in equivalent levels of serum cotinine found in humans. According to findings, ApoE-/- mice on a WD exposed to ENDS showed a marked increase in hepatic lipid accumulation in comparison with ApoE-/- on a similar diet exposed to saline aerosol. Functional analysis shows that lipid metabolism, cholesterol biosynthesis and circadian rhythm genes have been altered most significantly in the liver as a result of ENDS. These outcomes show profound negative effects of ENDS on the liver. This information is important for regulatory agencies, as they regulate ENDS.