PADI4 and cancer: In contrast to the established role of PADI3 in remodeling of intermediate filaments, PADI4 is associated with self-renewal and stemness (25), involved in NETosis (a program for formation of neutrophil extracellular chromatin traps) (26), and is up-regulated in several types of cancer (27), suggesting that the mechanism of action of PADI4 is distinct from that of PADI3.