HSP90AA1 and Motor neuron atrophy: In addition, HSP90 inhibitors, including 17-AAG and 17-DMAG, were found to be effective in ameliorating polyglutamine-mediated motor neuron degeneration in a mouse model of spinal and bulbar muscular atrophy (SBMA) through inducing the expression of HSP70 and HSP40 proteins27,28.