On the other hand, Th17 cells might paradoxically have antitumor functions in NSCLC: high Th17 cell counts in pleural effusion are related to better survival of NSCLC patients (187), and IL-21 secreted by Th17 cells could induce the expansion of cytotoxic CD8+ T cells (188). The gene discussed is IL21; the disease is non-small cell lung carcinoma.