B Quantitative PCR of FBXO5 transcripts in FACS-sorted cells with moderate or high levels of E2F7/8 expression, after 8 hours of doxycycline treatment. To avoid bias from cell cycle defects, cells were released from HU arrest at the onset of doxycycline treatment, resulting in a strong enrichment of cells in late S or G2 of both vehicle and doxycycline-treated cells (see Fig EV3C). 