IL6 and lung cancer: Another study has shown that smoking exposure combined with nontypeable H. influenzae can promote the metastasis and proliferation of lung cancer because smoking can promote bacterial translocation.[71] Moreover, IL-6 may play an important role in lung cancer by promoting COPD-like inflammation.[72] Microorganism-induced Th17 cells can promote the proliferation and angiogenesis of lung cancer cells.[73] In general, these evidences may be the key to inhibiting tumor development by maintaining homeostasis of host immune.