This protein was later renamed Coa4 (cytochrome c oxidase assembly number 4) and its involvement in CIV assembly was confirmed being identified as a genetic suppressor of mutations in Shy1 modeling those found in the human ortholog SURF1 and associated with Leigh syndrome (Petruzzella et al., 1998; Zhu et al., 1998; Bestwick et al., 2010b). This evidence concerns the gene SURF1 and Leigh syndrome.