PLA2R1 and idiopathic membranous glomerulonephritis: Four of these cases had IgG subtyping available; 1 HIV-associated mesangial proliferative GN was IgG1 dominant (2+) with weaker IgG3 and IgG4 (1+); 3 of the cases with anti-PLA2R-antibody-associated MGN were either IgG4 dominant or co-dominant.