ATP-binding cassette (ABC) transporters, alongside ion channels and aquaporins, are ubiquitous membrane-bound proteins that move substrates across extra and intra cellular membranes. Multidrug resistance-associated protein 1 (MRP1) is a member of the superfamily of ATP-binding cassette (ABC) transporters, and in humans is encoded by the ABCC1 gene. In addition to endogenous substrate exchange, ABC transporters also participate in the movement of drugs and chemicals across cell surface and cellular organelle membranes, suggesting that defects in these genes are of great im