PAX5 and neoplasm: While establishing Pax5Jak2/+ tumor cells in culture, we noticed that IL‐7 strongly stimulated the proliferation of these cells (Appendix Fig S7A), which is consistent with expression of the IL‐7 receptor on these cells (Fig 1I) and with a recent report demonstrating that the IL‐7 sensitivity of leukemic B cells is increased upon Pax5 loss (Ramamoorthy et al, 2020).