When we integrated several of these genes into a multivariate LASSO regression model to define poor tumour outcome in the BX‐Neu+ mouse cohort (Figure 5D,E and Table S5), four genes were identified that were associated with poor survival in BX‐Neu+ mice: Oip5, Higd1a, Shc4 and Scrg1 (Figure S5D–F). This evidence concerns the gene ERBB2 and neoplasm.