Phase contrast microscopy showing primary human mesangial cells in culture. Quantification of cell area showed that exposure of mesangial cells to the pro-fibrotic growth factor (TGF-β1) induced morphological cell expansion and hypertrophy, which was reversed following the overexpression of miR-378. Interestingly, transfection of a miR-378 inhibitor induced the expansion of mesangial cells, highlighting the regulatory role of miR-378 in mesangial hypertrophy. Please see the article by Wang et al. (pages 411-423).