Another interesting difference in our TK2-deficient cohort of patients compared with other pediatric mitochondrial myopathies is that the inflammatory infiltrates that were present were mainly constituted by macrophages with few T-lymphocytes that were associated with an overexpression of MHC I, especially in younger patients, where inflammatory infiltrates are not related only to myonecrosis. Here, TK2 is linked to Mitochondrial myopathy.