GPNMB and melanoma: To verify the specificity of the two binders toantigens expressedon the cell surface, we first tested the surface expression of GPNMBor VCAM-1 on parental 293T cells, 293T cells isogenically expressingGPNMB (293T-GPNMB) or VCAM-1 (293T-VCAM-1), and cancer cell linessk-mel-28 (human melanoma cell line) and HuT-78 (human cutaneous T-lymphocytecancer cell line), which intrinsically express GPNMB or VCAM-1, respectively.The cells were tagged with a commercial antihuman GPNMB antibody andantihuman VCAM-1 antibody.