The observed increase in PAD isozymes and protein deimination in the current study in human PD post-mortem brains correlates with our recently published animal study identifying increased PAD levels and protein deimination in brains and plasma of pre-motor PD animal models, where furthermore we also found raised levels of plasma-extracellular vesicles (EVs) with a modified content of deiminated proteins [14]. Here, PADI4 is linked to Parkinson disease.