This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Plasma levels of LDL-cholesterol, a key cardiovascular risk factor, are directly related to the fractional absorption of dietary cholesterol. Genetic differences between individuals contribute significantly to differences in cholesterol absorption. Recently a gene NPC1L1, encoding a membrane protein has been implicated in mediating transport of dietary cholesterol from the gut lumen into enterocytes. The goal of this project is to determine if sequence variations in NPC1L1 contribute to differences in fractional absorption of cholesterol.