BCRP contains only six transmembrane helices and one nucleotide-binding domain located toward the N terminus, and is often referred to as a half ABC transporter. The expression pattern of BCRP is similar to P-gp and it plays a protective role by extruding metabolites, toxins and xenobiotics. BCRP limits the oral absorption of its substrates and may cause clinically significant DDIs. BCRP limits the penetration of its substrates into the CNS; therefore, eliminating both P-gp and BCRP interactions have become an attractive strategy for improving the delivery of drugs to the CNS.
