GPNMB (Glycoprotein Nonmetastatic B) is a transmembrane glycoprotein encoded by the human gene GPNMB, belonging to the immunoglobulin superfamily. Below is a detailed introduction to the GPNMB protein. GPNMB is involved in interactions between cells, promoting cell adhesion and migration, which is particularly important in embryonic development and tissue repair. As a cell surface antigen, GPNMB plays a crucial role in regulating immune responses. It can influence macrophage polarization and modulate inflammatory responses. GPNMB has been found to be highly expressed in various cancers, such as melanoma, breast cancer, and lung cancer. Research indicates that it may contribute to tumor progression by promoting the survival, proliferation, and metastasis of tumor cells. Research on the GPNMB protein is ongoing, with the scientific community exploring its roles in various biological processes and its potential as a therapeutic target for diseases. Moreover, advancements in technology (such as single-cell RNA sequencing and high-throughput screening) provide new opportunities for a deeper understanding of GPNMB's functions and regulation.