CITED2 and breast cancer: Suntag-KRAB repression at the CITED2 enhancers confirms that CI54 most significantly affects transcription (Supplementary Fig. 7F), while Cas9-mediated CI54 deletion in the CITED2 expressing AR+ breast cancer cell line MDA-MB453 did not result in a transcriptional decrease, as this cell line does not use enhancer CI54 (Supplementary Fig. 7A, G, H).