Cl-amidine [68] is a pan-PAD inhibitor, and although more recent and PAD-isozyme specific inhibitors have been developed [69,70,71,72,73,74,75,76,77,78,79,80,81], Cl-amidine was used here as a first proof of principle for PAD-modulation in GBM, particularly as Cl-amidine is an effective EV inhibitor in various cancer cells [14,17,19,20] and promotes CNS repair [37,38,61]. Here, PADI4 is linked to cancer.