In MRL/lpr lupus-prone mice, the pan-PADI inhibitor ameliorated organ injuries by reducing NETs formation (Knight et al., 2015), but the genetic deletion of PADI4 in lupus model mice (Kienhöfer et al., 2017) and human neutrophil in vitro studies (pan-PADI inhibition in immune complexes-mediated NETs) (van Dam et al., 2019) showed conflicting data. This evidence concerns the gene PADI4 and systemic lupus erythematosus.