On the contrary, the loss of Pax5 is critical for ETV6/RUNX1+ B-ALL developed, as the onset of the disease in Sca1-ETV6-RUNX1 + Pax5-het mice (62.5%) is drastically increased even in the absence of exposure to infections, compared to Sca1-ETV6-RUNX1 mice (10.75%) and exposed to infections (Rodriguez-Hernandez et al., 2017a). This evidence concerns the gene RUNX1 and acute lymphoblastic leukemia.