E2F1 and cancer: Basal-like triple-negative breast cancers manifest a signature of overexpression of the miR-17∼92 (iR-17, miR-18a, miR-19a, miR-20a, miR-19b-1, and miR-92a-1) and miR-106b-25 clusters; the proto-oncogene cMYC regulates the former to modulate the critical transcription factor E2F1, resulting in cancer proliferation.