NPC1L1

Plays a major role in cholesterol homeostasis. Critical for the uptake of cholesterol across the plasma membrane of the intestinal enterocyte. Involved in plant sterol absorption, it transports sitosterol, although at lower rates than cholesterol (By similarity). Is the direct molecular target of ezetimibe, a drug that inhibits cholesterol absorption and is approved for the treatment of hypercholesterolemia. May have a function in the transport of multiple lipids and their homeostasis, thereby influencing lipid metabolism regulation. May be involved in caveolin trafficking from the plasma membrane (By similarity). In addition, acts as a negative regulator of NPC2 and down-regulates its expression and secretion by inhibiting its maturation and accelerating its degradation..

Function from UniProtKB (Q9UHC9), read 2026-09-23. CC BY 4.0.