C3 and glomerular disorder: Given the concern for MGRS—specifically, PGNMID—from the biopsy findings, the following labs were sent: cryoglobulin, urine and serum immunofixation studies, C3 nephritic factor (C3NeF; hemolysis-based, C3 convertase stabilization assay), complement factor H, anti-CFH, circulating immune complex (including anti-C3b), and Machaon gene panel for C3 glomerulopathy.