Alpha-1 antitrypsin deficiency -- Serpins and serpinopathies -- Alpha-1 antitrypsin biology -- Alpha-1 antitrypsin gene, genetic heritage, phenotypes, and genotypes -- Alpha-1 antitrypsin deficiency -- Alpha-1 antitrypsin deficiency -- Genetic epidemiology -- Laboratory diagnosis -- Clinical diagnosis -- Liver disease associated with Alpha-1 antitrypsin deficiency -- Respiratory manifestations of the Alpha-1 antitrypsin deficiency -- Other diseases associated with Alpha-1 antitrypsin deficiency -- Clinical management and treatment of lung disease -- Registries and patients' associations -- Current research and future perspectives.