We next aimed to confirm that the specific significant delay in B-ALL development due to IL-6+/- heterozygosity does not modify the B-cell susceptibility and genetic characteristics of B-ALL in Pax5+/- mice; similar to IL-6+/+/Pax5+/- mice, preleukemic IL-6+/-/Pax5+/- littermates presented a significantly reduced amount of total B-cells in the PB when compared to Pax5+/+ (WT) littermates of the same breeding (Supplementary Fig. 9), but this PB B-cell decrease was similar to the one observed in IL-6+/+/Pax5+/- mice (Supplementary Fig. 9). The gene discussed is IL6; the disease is precursor B-cell acute lymphoblastic leukemia.