In the lung of patients with NSCLC, we found IL-9+ cells induced in the tumoral region of the lung as compared to the control region (Figure 1B). While no induction of epithelial cells expressing IL-9 was noted in NSCLC patients, we identified tumor infiltrating T cells in NSCLC as important IL-9 producers (Figures 1G, H). The gene discussed is IL9; the disease is non-small cell lung carcinoma.