Inflammatory diseases of the lung are common, cause significant morbidity, and can be refractory to therapy.In some respiratory conditions, acute inflammation can convert to chronic inflammation, usually with the recruitment of the adaptive immune system, and chronic airway inflammation is part of the pathogenesis of many common lung diseases,including chronic obstructive pulmonary disease (COPD), allergic asthma and lung cancer.Biomarkers are currently widely used to diagnose diseases, monitor treatments, and evaluate potential drug candidates.However, the biomarker identification method, which strictly uses gene expression profiles, cannot show how the different genes within the biomarker gene set are related to each other.Further, the gene lists obtained from similarly diagnosed patients by different research groups differ widely and share few common genes.Due to these kinds of limitations, network biomarkers in lung inflammation, identified from the systems perspective,have the potential to open new avenues of research into the mechanisms of lung inflammation and the development of novel diagnostic and therapeutic strategies for human lung diseases.