TK2 and myelodysplastic syndrome: In the cDNA microarray we included 4 unrelated patients with MDS and mutations in TK2 (patients 1, 2, 3 and 4, MDS group), 4 patients with large mtDNA deletions as disease control group (patients 5, 6, 7 and 8, MDEL group) and 4 aged-matched healthy individuals (normal control group) (Table 1).