For example, researchers have created various cell models of MELAS harboring the m.3243A > G mutation (MT-TL1), Leigh syndrome harboring the m.9185T > C (MT-ATP6) and m.13513G > A (MT-ND5) mutations, LHON harboring the m.11778G > A (MT-ND4) mutation, and LHON harboring the patient-specific double mutations m.4160T > C (MT-ND1) and m.14484T > C (MT-ND6) [51,71,118,119,120,121,122,123,124]. Here, MT-ND4 is linked to Leigh syndrome.