First, to assess the display of human- and avian-type flu receptors in the peripheral airway epithelium of patients with COPD and controls, formalin-fixed, paraffin-embedded lung sections (COPD n = 5, control n = 5) were stained with (1) FITC-SNA, which specifically binds to sialic acids bound to galactose by the α2,6 linkage (SAα2,6Gal), the human-type flu receptor (Ito et al., 1997) and (2) a monoclonal antibody (clone HYB4) that specifically binds to SAα2,3Gal, the avian-type flu receptor (Hidari et al., 2013). The gene discussed is SAA2; the disease is chronic obstructive pulmonary disease.