ChIP-seq: was performed as described in Schlesinger and Goff, 2013. In short, cells from different time points after dox addition, with and without 4 days retinoic acid (4dRA) treatment, were collected and fixed. IP was done using Magna ChIP kit (Millipore) and DNA was purified using QIAquick PCR purification kit (Qiagen). ChIP Grade HA tag antibody was used (ab9110 from Abcam). 3'-end RNA-seq: Extraction, library preparation and sequencing was done using the RNesay kit (Qiagen) according to the manufacturer’s instructions, library preparation was done with QuantSeq 3′ mRNA-Seq Library Prep Kit by Lexogen. Four RNA libraries were prepared: from ESCs and 4dRA cells without or with 4h Dox addition. Libraries were subjected to single-end sequencing using Illumina Next-Seq 500 platform. ChIP-seq: Libraries were prepared as previously described (Blecher-Gonen et al., 2013).