HDL-mediated RCT. ABCA1 is involved in transfer of free cholesterol (FC) and phospholipids (PL) from macrophages to apoA-I. Lecithin cholesterol acyltransferase (LCAT) converts FC to CE. CETP and PLTP modify HDL by transferring CE and PL between HDL and triglyceride-rich lipoproteins. HDL delivers cholesterol to liver via SR-BI–mediated selective uptake of the lipids.