We selected two MMTV-p140Cap lines with a strong p140Cap expression in the mammary gland (see Supplementary Fig. 4 for detailed characterization of the Tg mice) that were crossed with both FVB-MMTV-NeuT29 and BALB/c-MMTV-NeuT27, 28 mice, which display different tumour onset times, to generate p140-NeuT mice. This evidence concerns the gene SRCIN1 and neoplasm.