B2M and membranous glomerulonephritis: Independently, using scRNA-seq, Chen et al. analyzed kidney biopsies affected by IgA nephropathy, lupus nephritis and membranous nephropathy and showed that podocytes from all these etiologies had increased expression of FXYD5, CD74, B2M (beta-2 microglobulin, a component of MHC class I molecules) when compared with a healthy donor (20).