PAX5 and acute lymphoblastic leukemia: We observed that B-ALL appeared in Pdcd1fl/fl;Mb1-Cre;Pax5+/− mice, where 46% (13 out of 28 mice) developed the disease, closely resembling the incidence, latency and overall survival of Pax5+/− animals (ns, p-value = 0.8336) (Figure 3A).