To assess the effect of CD25 (Il2ra) knockout on signaling in pre-B leukemia, pre-B cells from CD25-floxed mouse bone marrow were grown ex-vivo with IL-7 and transformed with BCR-ABL1, before tratment with 4-OHT to induce CD25 KO. Phospho-Tyrosine proteomics was performed and differential phosphosites analysed in Cre-ERT2 vs ERT2 samples.