Multidrug Resistance-Associated Protein (MRP) refers to a family of proteins that play a crucial role in the transport of various substances across cell membranes. These proteins help in the efflux of drugs and other compounds, which can lead to the phenomenon of multidrug resistance in cancer cells. By pumping out therapeutic agents, MRPs can reduce the effectiveness of chemotherapy, making treatment more challenging. MRPs are part of the ATP-binding cassette (ABC) transporter superfamily and are found in many tissues throughout the body. They are particularly important in organs like the liver, kidneys, and intestines, where they help in the detoxification and elimination of harmful substances. Understanding MRPs is essential for developing strategies to overcome drug resistance in diseases such as cancer and HIV.