Importantly, we observed that exosomes can package mitochondrial proteins (e.g., cytochrome c), which increased release from HD cells might constitute a mechanism that relates with decreased Cx-III subunit expression and activity; although its physiological relevance is still unclear, exosomal release of mitochondrial components may constitute a cell survival mechanism in response to oxidative stress and mitochondrial dysfunction (Phinney et al., 2015). Here, CYCS is linked to Huntington disease.