To gain insight on the molecular cause of the CI enzyme activity decrease in renal oncocytomas [4, 5], we performed WES of renal oncocytomas and their matching healthy kidney tissues with the aim to isolate all somatic mutation signatures showing 200X minimum sequencing coverage across the targeted bases, and minimum read depths of 61.21X (Supplementary Table 1). This evidence concerns the gene NDUFB6 and kidney oncocytoma.