Immunohistochemical staining for PRKD1, immunoglobulin kappa constant (IGKC), and UBE2W in normal kidney tissue and kidney tissue with IgA nephropathy (IgAN). (A, C, E) No significant staining for PRKD1, IGKC, or UBE2W was observed in glomeruli and tubules in normal kidney. However, there was (B) a patchy staining within podocytes and increased staining within tubular cells for PRKD1, (D) increased staining for IGKC in the glomerular endothelium and proximal tubules, and (F) increased staining of the proximal tubular region for UBE2W in kidney tissue with IgAN.