PLA2R1 and lupus nephritis: Noteworthy, both BAFF/BLyS and APRIL baseline serum levels in MN patients were comparable with those in patients with lupus nephritis (5.64 ± 0.97 vs. 6.01 ± 2.68 ng/mL for BAFF, p = 0.09; 3.62 ± 0.84 vs. 4.09 ± 2.24 ng/mL for APRIL, p = 0.18), while these cytokines were detected at very low concentration in MN patients without anti-PLA2R antibodies (1.08 ± 0.33 ng/mL for BAFF, 0.89 ± 0.19 ng/mL for APRIL) and in healthy volunteers (0.31 ± 0.21 ng/mL for BAFF, 0.52 ± 0.32 ng/mL for APRIL) (Figures 2(a) and 2(b)).