DNAJB1 and Machado-Joseph disease: Although evidence levels remain preliminary, the paragraphs below address promisingadditional biomarkers due to their direct roles in the SCA3/MJD pathophysiology.Molecules associated to quality control systems might play a very relevant role inSCA3/MJD, and we can highlight here two promising ones: beclin-1 and DNAJB1.Beclin-1 is a marker of protein quality control systems, and low protein as well asmRNA levels were found in fibroblasts from symptomatic SCA3/MJD individuals (Nascimento-Ferreira et al.,2011; Onofre et al.,2016).