The endogenous pathway involves the liver synthesizing lipoproteins. TG and cholesterol ester are generated by the liver and packaged into VLDL particles and then released into the circulation.

Inside cells, cholesterol is esterified to provide protection from the toxicity of free cholesterol. Local excesses can overwhelm this protective mechanism and cells have no internal mechanism for ...

enabling its conversion into cholesterol ester for further distribution. Mice lacking Asters showed reduced cholesterol absorption and were protected from diet-induced high cholesterol.