PAX5 and acute lymphoblastic leukemia: Conversely, the loss of Pax5 in Pax5Jak2/+Rosa26BirA/+ B‐ALL cells resulted in a similarly high number and extensive overlap of the Pax5‐Jak2 peaks compared with the Pax5 peaks identified in Pax5Bio/Bio pro‐B cells, although the binding density was still higher for full‐length Pax5 compared with Pax5‐Jak2 (Fig 5B and Appendix Fig S5C and D).