MT-ND4 and oncocytic adenoma: In our original work which introduced DdCBE4, we found that installing a truncating, oncocytoma-associated MT-ND4 mutation using the MT-ND4 DdCBE (hereafter ONC DdCBE) resulted in cell populations approaching 50% bulk heteroplasmy, and here we investigated the heteroplasmy distribution of the edited cells.