Moreover, we found that iAMP21-ALL PDX cells with SH2B3 bi-allelic deletions were more sensitive to IL7 induced STAT5 activation than those with wild type SH2B3. Evidence is also accumulating that in B-ALL, loss of SH2B3 function cooperates with abnormalities in addition to those of chromosome 21. Here, IL7 is linked to precursor B-cell acute lymphoblastic leukemia.