As shown in Figure 1, bulk CTL activity induced by ACE from Ova-1, Ova-2 and Ova-3 primary tumour cells could be demonstrated against the respective autologous tumour cells (Figure 1, left panel) as well as against the HER-2/neu+ ovarian cell line SKOV3 transfected to express HLA-A2.1 (SKOV3.A2; provided by Dr C-G Ioannides, Department of Gynecologic and Oncology and Immunology, university of Texas, MD Anderson Cancer Center) and the HER-2/neu+ HLA-A2.1+ breast cancer cell line MCF-7 (Figure 1, right panel). This evidence concerns the gene ERBB2 and breast carcinoma.