Quantification of IL-9 expressing cells in the ileum and colon from mice with CML revealed that an average of 92% and 95% of all IL-9+ cells in the ileum and colon, respectively, were CD3−GATA3+, providing further confirmation that these cells were ILC2s (Fig. 6h). This evidence concerns the gene IL9 and chronic myelogenous leukemia, BCR-ABL1 positive.