CCNE1 and breast cancer: Considering that E2F8 is identified to activate the VEGFA promoter through cooperation with other transcriptional activator HIF1 [25], or the cyclin D1 promoter by blocking the occupancy of other E2Fs [29], it would be of great interest to investigate whether E2F8 may regulate CCNE1, and CCNE2 gene expression in breast cancer by either cooperating with other transcriptional activators or blocking the occupancy of other E2Fs.