Our study, for the firsttime, demonstrated that the inductionof the NRF2-ARE pathway stimulated by HC treatment in SCA patientswas not associated with an antioxidant response in reticulocytes.This finding, along with our ATF4 results and existingliterature, suggests a potentially distinct role for NRF2 and ATF4signaling in reticulocytes under HC treatment. Here, ATF4 is linked to autosomal dominant cerebellar ataxia.