TGFB1 and glomerulosclerosis: Our in vitro experiments in cultured mesangial cells, an important cell type implicated in ECM accumulation in glomerulosclerosis, showed that JQ1 inhibited the gene expression and the production of several ECM proteins induced by TGF-β1, including COLI and COLIV, demonstrating that the inhibition of BET proteins directly limited ECM protein expression.