The potential relevance of molecules, such as (in blood) eosinophil cationic protein, periostin, lipoxins, chitinases, YKL-40, (in exhaled breath) fractional exhaled nitric oxide, volatile organic compounds, evaluation of exhaled breath temperature, (in urine) bromotyrosine, metabolites of eicosanoids, eosinophil-derived neurotoxin in diagnostics and management of asthma were evaluated. The gene discussed is POSTN; the disease is asthma.