MCAT and oncocytic adenoma: The most commonly affected Complex I subunits in RO include MT-ND1, MT-ND5, MT-ND4, and MT-ND3, and they often present with high variant allele fractions (VAF) in oncocytomas (69–84%) and eosinophilic chromophobe RCCs (62%), and less frequently (<20%) in other renal malignancies [9].