PRKCB and primary membranoproliferative glomerulonephritis: PKC α and β gene expression was studied by quantitative real-time reverse transcription-PCR in 20 patients with type 2 diabetes and proteinuria (serum creatinine 2.04 ± 0.85 mg/dl, 24-h urinary protein 3.61 ± 1.75 g, eGFR 37.85 ± 17.89 ml/min/1.73 m2), 20 patients with proliferative LN (serum creatinine 1.67 ± 1.50 mg/dl, 24-h urinary protein 4.46 ± 5.01 g, eGFR 69.62 ± 40.93 ml/min/1.73 m2), and 20 patients with MPGN (serum creatinine 3.32 ± 2.79 mg/dl, 24-h urinary protein 4.65 ± 4.11 g, eGFR 32.62 ± 29.56 ml/min/1.73 m2).