As an important validation of the observations made in the yeast models, we haveconfirmed our HAP4 overexpression results in a fly model of HD, inwhich we have shown that overexpression of the Drosophila PGC-1αhomolog (DmPGC-1/spargel) is also able to protectagainst the behavioral deficits and neurodegeneration induced by polyQ proteins. The gene discussed is PGC; the disease is Huntington disease.