Almost all of this research has aimed to reveal how those at the higher ends of the repeat distribution differ from the norm, and the focus has been on pathological functioning, including fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated premature ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND) [1,2]. Here, PSMB5 is linked to fragile X-associated tremor/ataxia syndrome.