PMEL and metastatic melanoma: Tumor-specific antibodies directed against MDA (TRP1/TYRP1, TRP2/TYRP2, gp100, MelanA/MART1) and against the C/T antigen NY-ESO-1 are candidate biomarkers that may complement patient assessment in association with PD-L1 status and/or TILs, with the aim to predict outcomes of CI treatment in patients with metastatic melanoma.