CYCS and type 2 diabetes mellitus: In T2DM, many toxic metabolites (e.g., fatty acids) interfere with the mitochondrial electron transport chain and induce a large amount of ROS.[34] As a result, mitochondria are damaged readily by ROS and then release apoptosis factors (e.g., cytochrome c, Cyt c) to induce β cell death.[35] Mitophagy degrades dysfunctional mitochondria selectively before damaged mitochondria activate cell death.