B2M and neoplasm: IHC of cases 55, 56, 120, and 179 (the 4 HLA-A and -B negative cases) showed complete absence of HCA2 and HC10 staining in tumor cells, and decreased anti-β2-m staining which was primarily cytoplasmic (see Figure 3) and, consequently, probably irrelevant since cytoplasmic localization of HLA molecules is not functional.