PINK1 and diabetes mellitus: Surprisingly, in streptozotocin-induced diabetic rat models, renal cortex PINK1 expression is increased in early diabetes (Smith et al., 2012), indicating that mitophagy could be activated to clear dysfunctional mitochondria from the kidney during early-stage diabetes, but becomes overwhelmed as DKD progresses, resulting in accumulation of fragmented mitochondria and induction of cell death (Higgins and Coughlan, 2014).