CDK12 and neoplasm: SEs recruit an extreme density of transcription factors/cofactors, cyclin‐dependent kinases (e.g., CDK7 and CDK12) and epigenetic regulators to synergistically drive transcriptional activity, which play a critical role in cell identity, proliferation, survival, etc.6SEs are also acquired by tumour cells around key oncogenes, such as XBP1,7PAK4,8MYCN.9