In the context of PD, loss of NUS1 expression (NUS1 has been shown to be enriched for rare nonsynonymous mutations in PD cases [6]) in D. melanogaster, and has been shown to reduce climbing abilities of the flies (which is a hallmark of D. melanogaster ageing [21,22]), reduce the level of dopamine, and reduce the number of dopaminergic neurones within the flies [6]. This evidence concerns the gene NUS1 and Parkinson disease.