Immunohistochemical analysis of tumor specimens. Expression of NY-ESO-1 and HLA class I was analyzed in four esophageal cancers (E-1, E-2, E-3 and E-4) and a malignant melanoma (M-1) using E978 and EMR-5 mAbs, respectively. Magnification was 200x, except for NY-ESO-1 expression in E-3 which was 80x.