Lastly, to further confirm the role of JunD/RSK3 signalling in BET resistance, RPS6KA2 and JUND were respectively knocked down in two JQ1-resistant breast cancer cell lines (BT474 and MDA-MB-453) (Supplementary Fig. 3B), and showed that the silencing of both RPS6KA2 and JUND restored the JQ1 sensitivity of these cells (Fig. 3f). This evidence concerns the gene RPS6KA2 and breast carcinoma.