Analysis of DIOPT paralogy data and InterPro domain data reveal three previously unidentified/named genes encoding paralogous subunits of mitochondrial complex IV (cytochrome c oxidase): 1. CG31644 is a paralog of cype (COX6C); it should be named 'COX6CL' to be consistent with current nomenclature. 2. CG34172 is a paralog of COX7A and COX7AL; it should be named 'COX7AL2' to be consistent with current nomenclature. 3. CG44296 is a paralog of COX7C; it should be named 'COX7CL' to be consistent with current nomenclature.