This cluster of papers focuses on the intricate mechanisms of cholesterol metabolism, including the roles of key regulators such as LXR and SREBP, the impact on atherosclerosis, and the involvement of specific proteins like ABCA1 in processes such as cholesterol efflux from cells. It also delves into the effects of phytosterols on lipid levels and the interplay between cholesterol homeostasis and inflammation in conditions like atherosclerosis.