MUL1 and Parkinson disease: Since mutations in VPS35 have been identified in multiple PD families (Vilarino-Guell et al., 2011; Zimprich et al., 2011; Kumar et al., 2012; Lesage et al., 2012), it will be particularly interesting to determine if PD-associated mutations in VPS35 have effects on MUL1-dependent degradation of Mfn.