Results . IL-9 promotes tumor growth and alters lung macrophage populations . The anti-tumor effect of Th9-derived IL-9 has been well characterized, particularly in subcutaneously injected tumor models2 , 3 , 5 , 9. However, contrasting studies indicated that IL-9-deficiency inhibited lung tumor metastasis10. To detect how IL-9 signaling affects disease progression of lung cancer patients, we performed a Kaplan-Meier survival analysis of 982 lung cancer patients from m...