NY-ESO-1 expression in metastatic melanoma. (4) Metastatic melanoma with focal NY-ESO-1 expression. The positive cells are intermixed with negative cells. (5) Metastatic melanoma case with moderate NY-ESO-1 expression. Note the heterogeneous mosaic-like immunostaining pattern. (6) Metastatic melanoma with diffuse NY-ESO-1 expression.