The candidate drug is in phase 3 clinical forthe early-stage and symptomatic treatment of Huntington’s disease,16−18 and in phase 2 for the treatment of levodopa-induced dyskinesiain Parkinson’s disease patients.19 Cutamesine (SA4503) is an S1R agonist with selectivity over 36 otherreceptors, under phase 2 clinical trial in subjects with major depressivedisorder, able to restore motor function after acute ischemic stroke.20,21 The selective S1R antagonist E-52862 (S1RA) has been evaluated ina phase II clinical trial for the treatment of neuropathic pain ofdifferent etiology. This evidence concerns the gene TMBIM4 and juvenile Huntington disease.