ATXN3 and neurodegenerative disease: However, given their clear increase and high intraindividual stability, both markers might still be further explored as combined fluid biomarkers in future longitudinal SCA3 trials, as they might show differential responses and dynamics to disease‐modifying treatments or capture different features underlying multifaceted neurodegeneration, as suggested for other neurodegenerative diseases (Poesen & Van Damme, 2018; De Vivo et al, 2019; Winter et al, 2019).