BRD4 and cancer: BRD4 is an epigeneticregulator that plays a significant role in cancer.38 Post-translational modifications (PTMs) of BRD4, such asphosphorylation, methylation, and ubiquitination, are well studied;its phosphorylation was reported to affect chromatin targeting, onco-factorsrecruitment, and cancer progression.39 However,the O-GlcNAcylation of BRD4 has never been studied comprehensivelydue to the lack of appropriate tools.