Eating your mitochondria-when too much of a good thing turns bad.

How mitophagy is turned on to remove damaged or excess mitochondria from cells has been well-studied, but less is known about how the pathway is turned off to avoid "over-eating" of mitochondria under basal conditions. Three new studies now reveal the disease-associated FBXL4 protein as an important negative regulator of constitutive mitophagy, controlling the stability of mitophagy receptors BNIP3 and NIX.