Additional file 6: Figure S4. Activation of PINK1 prevents the impaired maturation of hiPSC-CMs caused by PINK1 deletion. (A) α-actinin staining of kinetin treatment of hiPSC-CMs and after deletion of PINK1 in hiPSC-CMs. α-actinin (green). Scale bar = 20 μm. (B) Electron microscopy images of kinetin treatment of hiPSC-CMs and hiPSC-CMs deficient in PINK1. ImageJ assay Z-band width (C) and sarcomere length (D). Scale bar = 1 μm. (E) MitoTracker staining of kinetin treatment of hiPSC-CMs and after deletion of PINK1 in hiPSC-CMs. MitoTracker (green). Scale bar = 20 μm. The means ± SEMs are shown. **P < 0.01, ***P < 0.001.