E2F1 and breast neoplasm: For example, AIB1 can increase the function of Ets (E-twenty six) family transcription factors PEA3, AP-1 and E2F1, the activity of the IGF1 signaling pathway, epidermal growth factor (EGFR) and ERBB2, and the expression of MMPs to promote breast-tumor cell proliferation, migration, invasion and metastasis [20], [23].