SERPINA1 and COVID-19: Furthermore, the decrease in intensity of the 52 kDa band in favor of that at 80 kDa (lanes 6 and 8 of Figure 1) upon incubation with exogenous HNE (2 μL; 0.2 mg/mL) demonstrated the capacity of AAT present in these samples to bind HNE, in contrast to what observed in COVID-19 samples.