GPNMB and neoplasm: A study showed that GPNMB can attenuate the activation of T cells that are activated via syndecan-4, allowing the evasion of melanoma cells for immunological recognition and destruction (40), whereas the blockade of GPNMB by antibodies restores the integrity of T cells, attenuates tumor growth, and increases IFNγ levels in the tumor microenvironment (81).