(C) Cell viability was determined in Null- or TFEB/3 knockout-MEF cells incubated in the presence of DMSO (Control) or Tunicamycin (Tun.) (0.1 µg/ml) for the indicated times (mean ± SD of the percentage of viable cells compared to control from three independent experiments, one-way ANOVA analysis versus the corresponding time point in Null-MEF cells ***p < 0.001). 