In addition, tubule-specific HDAC9 knockout reduced the protein level of PCNA and α-SMA, especially in PDGRF-β-positive fibroblasts from fibrotic kidneys (Fig. 4h), suggesting HDAC9 deficiency in TECs inhibited proliferation and activation of fibroblasts in AAN. The gene discussed is HDAC9; the disease is Balkan nephropathy.