Transmembrane glycoprotein NMB (GPNMB) is also known as Transmembrane glycoprotein HGFIN, DC-HIL and Osteoactivin (OA), which belongs to the PMEL/NMB family. GPNMB contains one PKD domain. GPNMB is a transmembrane glycoprotein that is up-regulated in various cancer cells, including in glioblastoma multiforme and is expressed in many melanoma cells, as well as in tissue macrophages. GPNMB protein acts as a downstream mediator of BMP-2 effects on osteoblast differentiation and function. GPNMB participates in bone mineralization, and functions as a negative regulator of inflammation in macrophages.