title: Guest editorial.
authors.forename: P J
authors.initials: PJ
authors.lastname: Helms
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications; D016535:Bronchial Hyperreactivity / Q000150:complications; D002648:Child; D004198:Disease Susceptibility; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000209:etiology* / Q000235:genetics; D012135:Respiratory Sounds; D018570:Risk Assessment; D012720:Severity of Illness Index; D012907:Smoking