The CD68 protein is a heavily glycosylated transmembrane protein belonging to the lysosome-associated membrane glycoprotein (LAMP) family, primarily serving as a macrophage marker. With a molecular weight of approximately 110 kDa, it contains scavenger receptor-like cysteine-rich domains and participates in innate immune responses by binding specific ligands such as oxidized low-density lipoprotein (oxLDL). Localized to lysosomal and endosomal membranes, CD68 plays a crucial role in antigen presentation, inflammatory responses, and tissue repair. It is commonly detected via immunohistochemistry (e.g., using the PG-M1 antibody) and is widely utilized to identify tumor-associated macrophages (TAMs) and assess pathological progression in chronic inflammatory diseases, including atherosclerosis and rheumatoid arthritis.