HBB and chronic obstructive pulmonary disease: The expression levels of Hbα, Hbβ or their complexes did not differ significantly in the lungs of the controls, smokers or patients with COPD except for the assays done under reducing conditions for Hbβ i.e. the level of Hbβ monomer was higher (2.3 fold) in the control than in the COPD lungs.