C Quantification of mitochondrial clearance in U2OS:GFP−parkin cells treated as in (A), fixed and immunostained for TOM20. Data are shown as percentage of cells containing mitochondria, by TOM20 staining, visualized by fluorescence microscopy. Error bars represent the mean ± s.e.m. (n = 3 experiments, with at least 85 cells quantified per condition, per experiment). 