Several MPO inhibitors have been developed, including PF-2999 for cardiovascular diseases [12,13]; AZD3241 for Parkinson’s disease [14]; PF-1355 for vasculitis, glomerulonephritis, and MI [10,15]; AZD4831 for heart failure (NCT03136991) [16]; and verdiperstat for multiple system atrophy (MSA) (NCT05086094) and amyotrophic lateral sclerosis (ALS) (NCT04436510), among others. Here, MPO is linked to multiple system atrophy.