Using BALB/c-derived renal carcinoma (Renca) cells as a model system, we could show in the present study that the mono-epitope liposomes carrying the Tc-ErbB2 peptide induced protective cellular immunity against tumour cells expressing human ErbB2, resulting in the rejection of s.c. implanted Renca-lacZ/ErbB2 cells in the majority of the vaccinated animals. The gene discussed is ERBB2; the disease is renal carcinoma.