Lung

The lung is the primary organ of the respiratory system, facilitating the essential exchange of oxygen and carbon dioxide between the environment and the bloodstream [10]. It comprises a hierarchical structure of airways—trachea, bronchi, and bronchioles—that terminate in specialized air sacs called alveoli, where gas exchange occurs across a delicate epithelial-endothelial interface [7, 10]. The lung is not a singular molecular target; rather, it is a tissue environment containing diverse cell types (such as pneumocytes, macrophages, and endothelial cells) and numerous specific molecular targets like G protein-coupled receptors, ion channels, and tyrosine kinases [5, 7, 12]. In the context of drug development, the lung is the site of pathology for major conditions including asthma, chronic obstructive pulmonary disease (COPD), and lung cancer, which are treated by targeting specific proteins within the pulmonary architecture [1, 2, 4]. Therapeutic agents are often delivered via inhalation to achieve high local concentrations at the site of disease while reducing systemic exposure and potential side effects [5]. Consequently, while the lung is the focus of many therapies, it is considered an organ/tissue system rather than a discrete target molecule [5, 10].

Other names

Pulmonary organRespiratory organ

Not applicable; the lung is a complex organ containing various molecular targets (receptors, enzymes, etc.) rather than being a single therapeutic target itself.