The ERK pathway is involved in glutamatergic and brain-derived neurotrophic factor signalling, both of which are impaired in Huntington’s disease.47 Interestingly, activating ERK1/2 has shown beneficial effects in multiple cellular and animal models of Huntington’s disease.48,49 CDK5 and PRKCG were both predicted to be activated in the striatum of Huntington’s disease mice, concordant with previous studies, reporting aberrant activation of CDK5 in striatal cells and Huntington’s disease mouse models.50,51. The gene discussed is MAPK3; the disease is juvenile Huntington disease.