Therefore, when we considered single variants only, there were 50 variants present only in tumor samples and most of them was distributed in four regions – MT-DLOOP1 (16%), MT-ND5 (16%), MT-ND4 (10%) and MT-DLOOP2 (10%) –, while there were eight variants present only in internal control samples, of which most was found in MT-ND5 (25%). This evidence concerns the gene MT-ND4 and neoplasm.