IL9 and chronic myelogenous leukemia, BCR-ABL1 positive: While there was no difference in spleen weight between groups (Supplementary Fig. 3d), the absolute number of myeloid CD11b+ Gr-1+ cells were also significantly augmented in mice that were treated with anti-IL-9 antibody (Supplementary Fig. 3e), demonstrating that IL-9 blockade increased the absolute number of granulocytes in CML mice.