AP2M1 also AP2u1 is a subunit of the heterotetrameric coat assembly protein complex 2 (AP2), which belongs to the adaptor complexes medium subunits family. AP2M1 plays a significant role in clathrin-mediated endocytosis, a vital cellular process for internalizing nutrients and signaling molecules. AP2M1 is primarily located at the plasma membrane and is essential for linking clathrin to specific receptors in coated vesicles, facilitating the transport of ligand-receptor complexes from the cell surface to intracellular compartments. Proper functioning of AP2M1 is critical for maintaining cellular homeostasis and regulating various signaling pathways, as disruptions in this process can lead to impaired endocytosis and contribute to various diseases, including cancer and neurodegenerative disorders.