Thus, vaccinated mice were protected against challenge with Renca-lacZ/ErbB2, but not against ErbB2-negative Renca-lacZ cells still expressing bacterial β-galactosidase, which in naïve animals in our Balb/c-based model fails to serve as a tumour rejection antigen (Maurer-Gebhard et al, 1998). This evidence concerns the gene ERBB2 and neoplasm.