Two patients (1 with HBV and 1 with malignancy) showed reactivity against PLA2R. Immunostaining for IgG4 was observed in both patients with anti-PLA2R reactivity but it was not present in patients with secondary MN without anti-PLA2R, except in one patient who showed equivocal IgG4 staining (Table 2). This evidence concerns the gene PLA2R1 and cancer.