Excitingly, a quantitative trait locus variant in PSMB5, PSMB5rs11543947-A, was found to be associated with decreased expression of PSMB5 and delayed onset of FXTAS in human FMR1 premutation carriers, thereby postulating this gene as important for the exploration of therapeutic strategies for FXTAS. This evidence concerns the gene PSMB5 and fragile X-associated tremor/ataxia syndrome.