PROS1 and alpha 1-antitrypsin deficiency: Furthermore, the Z-AAT protein from the most severe form of AATD is known to inhibit NSPs less avidly than normally folded AAT (M-AAT) (Korkmaz et al., 2005; Sinden et al., 2015), and spontaneous polymerization of the Z protein is also known to activate neutrophils, adding further complexity (McEnery et al., 2022) to the physiological effects in patients.