P-glycoprotein (P-gp), also known as MDR1 or ABCB1, is a member of the ABC transporter family. It consists of two ATP-binding domains and two transmembrane domains, primarily located on the cell membrane. P-gp is involved in the efflux of various drugs and toxins, reducing intracellular drug concentrations by utilizing ATP hydrolysis energy, thereby playing a crucial role in drug resistance and drug excretion. The expression of P-gp is tissue- and cell-specific, and mutations or dysregulation of its gene are associated with various diseases, including chemotherapy resistance in cancer, cardiovascular diseases, and intestinal absorption disorders.