MRP7 Background Information The MRP family is represented by nine similar ABC transporters that have the ability to transport structurally diverse lipophilic anions and operate as chemical efflux pumps. MRP7 (multidrug resistance-associated protein 7, ATP-binding cassette sub-family C member 10) is a multi-pass membrane protein that belongs to the ABC transporter family (conjugate transporter subfamily). MRP7 is involved with the ATP-dependent transport of 17b-estradiol-D-17-b-glucuronide (E217bG). MRP7 is also probably involved in cellular detoxification through its lipophilic anion extrusion capabilities. MRP7 contains two ABC transmembrane type 1 domains and two ABC transporter domains. MRP7 likely has three isoforms. Isoform 2 is the most widely expressed, while isoform 1 is predominately expressed in the spleen.