In the COPD combined IPA mouse model, the serum IL-17 level in the COPD+IPA group was significantly higher than that in the COPD group (17.96 ± 9.59 pg/mL vs. 8.05 ± 4.44 pg/mL, P = 0.02) (Geng et al., 2020). The gene discussed is IL17A; the disease is chronic obstructive pulmonary disease.