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. This evidence concerns the gene TK2 and gas gangrene.