PRTN3 and lupus nephritis: Anti-PAR 1 antibody levels were higher in lupus nephritis (n = 17) patients compared to those with membranous nephropathy (n = 18) (p = 0.0004), focal and segmental glomerulosclerosis (n = 25) (p = 0.00003), IgA nephropathy (n = 14) (p = 0.004), non-IgA mesangial proliferative glomerulonephritis (n = 6) (p = 0.007), and c-ANCA-positive vasculitis (n = 40) (p = 0.01) (Figure 2a,b).