Since the agent's cleavage site is the NE-specific substrate PMAVVQSVP [16] and the IC50 of NE over human PR3 is 23-times lower, it is very likely that the dominant neutrophil protease involved in NE680 activation is NE, and likely not PR3 or other off-target proteases associated with lung inflammation. This evidence concerns the gene PRTN3 and inflammation.