Plasma levels of TNF-α are elevated in rheumatoid arthritis (RA) (42), Henoch-Schonlein purpura (HSP) (43), immunoglobulin A vasculitis (IgAV) (44), chronic obstructive pulmonary disease (COPD) (45), psoriasis (PS) (46), and ankylosing spondylitis (AS) (47) and are associated with the severity of disease (42–47). This evidence concerns the gene TNF and chronic obstructive pulmonary disease.