Immunohistochemistry assessment of protein markers of mitochondrial biogenesis, fusion, fission, and autophagy in LV sections of FA patients relative to age- and gender-matched controls. Representative micrographs of staining for: (A) H & E, (B) PGC1α, (C) MFN1, (D) DRP1, (E) FIS1, and (F) P62 and their corresponding quantification in LV sections from FA patients and age- and gender-matched controls (see Table S1). Dash-encircled regions indicate areas of interstitial fibrosis; asterisks indicate areas of cardiomyocyte degeneration; and square-brackets indicate disorganized intercalated discs. Quantification of immunohistochemistry was performed using ImageJ Fiji with staining intensity represented as optical density (OD)/cardiomyocyte, where OD = log [max intensity/mean intensity]. Data are mean ± SEM (n = 10–12 specimens, 9–11 images were analyzed per specimen). Unpaired two-tailed Student's t-tests were used. *, p < 0.05; **, p < 0.01; ****, p < 0.0001 versus control. n.s., not significant. Scale bar: 50 μm.