PRTN3 and systemic lupus erythematosus: For example, citrullinated proteins (such as histone H3, histone H4 and vimentin) are new neoepitopes for anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA); NET-derived extracellular nucleic acids and dsDNA are the targets of systemic lupus erythematosus (SLE) autoantibodies; NET-associated MPO and proteinase 3 (PR3) enzymes are major autoantigenic targets of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) (8–10).