Niemann-Pick C1-Like 1 (NPC1L1) is a protein found on the gastrointestinal tractepithelial cells[5] as well as in hepatocytes.[6] Specifically, it appears to bind to a critical mediator of cholesterol absorption.
The drug ezetimibe inhibits NPC1L1 causing a reduction in cholesterol absorption, resulting in a blood cholesterol reduction of between 15-20%.[7] Polymorphic variations in NPC1L1 gene could be associated with non-response to ezetimibe treatment.[8]
NPC1L1 has been shown to be an accessory receptor for hepatitis C virus entry into cells, and thus ezetimibe might be used as a therapeutic strategy.[9]
As cancer appeared more frequently in patients treated with simvastatin-ezetimibe combination therapy in one clinical trial,[10] it had been hypothesized that NPC1L1 by ezetimibe might be associated with an increase cancer risk.[11] However a meta-analysis of ezetimibe clinical data showed no increased risk of cancer from treatment with ezetimibe.[12]
^Savarese G, De Ferrari GM, Rosano GM, Perrone-Filardi P (December 2015). "Safety and efficacy of ezetimibe: A meta-analysis". International Journal of Cardiology. 201: 247–52. doi:10.1016/j.ijcard.2015.08.103. PMID26301648.
Overview of all the structural information available in the PDB for UniProt: Q9UHC9 (Human NPC1-like intracellular cholesterol transporter 1) at the PDBe-KB.