(D) Chromatin condensation, an indication of cells undergoing apoptosis, was assessed in Null- or TFEB/3 knockout-MEF cells incubated in the presence of DMSO (Control) or Tunicamycin (0.1 µg/ml) for the indicated times. Confocal microscopy images were obtained from fixed cells stained with Hoechst 33342. Scale bar, 20 µm. Data are representative of three independent experiments. 