Immunogen sequence: LTNNILRIDC HWSAPELGQG SSPWLLFTSN QAPGGTHKCI LRGSECTVVL PPEAVLVPSD NFTITFHHCM SGREQVSLVD PEYLPRR. Human Interleukin 9 (IL9) was first identified based on its proliferative activity on a human myeloid leukemic cell line. Human IL9 stimu