P. aeruginosa-derived flagellin induces IL-6 and IL-8 production in bronchial epithelial cells through the phosphorylation of p38, ERK and JNK, which partially explains the underlying mechanism of P. aeruginosa causing acute exacerbation of COPD (Nakamoto et al., 2019). The gene discussed is CXCL8; the disease is chronic obstructive pulmonary disease.