Thus, we evaluated the ability of fE75 and fML to recognize physiological levels of peptide presented by the HLA-A2 molecule using flow cytometric analysis of several human tumor cell lines: MDA-MB-231 breast tumor cells (HLA-A2pos and HER2/neupos); SKOV3 HLA-A2 transfected ovarian tumor cells (HLA-A2pos and HER2/neupos); MCF7 breast tumor cells (HLA-A2pos and HER2/neupos); LNCaP prostate tumor cells (HLA-A2pos and HER2/neupos); and negative control SKOV3 ovarian tumor cells (HLA-A2neg and HER2/neupos). The gene discussed is ERBB2; the disease is prostate neoplasm.