Peak calling with a stringent P value of < 10‐10 identified 36,917 Pax5 peaks in Pax5Bio/Bio pro‐B cells, 2,717 Pax5‐Jak2 peaks in Pax5Jak2/+Rosa26BirA/+ pro‐B cells, and 34,068 Pax5‐Jak2 peaks in Pax5Jak2/+Rosa26BirA/+ B‐ALL cells (Fig 5B). This evidence concerns the gene JAK2 and acute lymphoblastic leukemia.