To that end, we found that expression of mMCP1,2,4, which is produced by both mucosal and connective tissue mast cells, was significantly increased in leukemic animals but reduced in anti-IL-9 antibody-treated mice (Fig. 4c), whereas mMCP-7 which is produced by connective tissue mast cells was reduced in CML mice (Fig. 4d). Here, IL9 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.