The Pax5Jak2/+ and control Pax5+/−Cdkn2ab+/− B‐ALL tumors were assigned by principal component analysis (PCA) between pro‐B and large pre‐B cells in early B cell development (Appendix Fig S2E) and yet differed from each other in expression (Appendix Fig S2F). This evidence concerns the gene PAX5 and acute lymphoblastic leukemia.