To test this possibility, we explanted two independent cell lines from the parental MMTV-NDL2-5 tumours and from ErbB2 induced tumours carrying both conditional FAK alleles (NDL2-5/FAKflx/flx) and infected them with empty vector controls or retroviral vectors expressing Cre recombinase (Figure 4). This evidence concerns the gene ERBB2 and neoplasm.