CD34 and chronic myelogenous leukemia, BCR-ABL1 positive: BRD4 has been found to be expressed in primary CML cells, CD34+/CD38− leukemic stem cells (LSC), and in the CML cell lines KU812, K562, KCL22, and KCL22T315I.462 Collaboration between BRD4 and DOT1L has been reported to be important in highly transcribed genes in proximity to super enhancers.