We next addressed whether at least two E2F activators were upregulated in a particular breast cancer subtype by mining the METABRIC database, which classified breast tumors by PAM50 intrinsic subtype analysis and found that higher percentages of basal, Her2+, and luminal B breast tumors co-overexpress at least two E2F activators (Table 1). This evidence concerns the gene ERBB2 and breast cancer.