Clinical characteristics of the participants
In the present study, EBC samples were obtained from a total of 309 participants, including 58 healthy controls and 251 patients with asthma (Table 1 ). The average age of the participants in the healthy control and asthma groups were 50.8 (SD 14.4) and 32.4 (SD 7.2) years, respectively. The sex ratio (women/men) of in the healthy control group was 1.6, while that in the asthma group was 2.4, i.e., it was skewed more toward women. The clinical characteristics of the 251 patients with asthma are detailed in Table S1 .