An earlier study showed that HDAC4 is required for TGF-β1-induced myofibroblastic differentiation, as inhibiting histone deacetylation by trichostatin A or silencing the expression of HDCA4 inhibited the transcription of the α-SMA gene [153], revealing a critical role for histone acetylation in renal fibrosis. The gene discussed is TGFB1; the disease is renal fibrosis.