Bortvedt el at discovered that in adult HD flies co-treatment of feeding cystamine and expressing a transgene encoding the anti-htt intracellular antibody (intrabody) C4-scFv leads to alleviation of photoreceptor neurodegeneration without benefit in longevity, however in larval and adult stages of Drosophila feeding cystamine showed opposite effect: longevity was prolonged without photoreceptor rescue [53]. The gene discussed is HTT; the disease is Huntington disease.