Finer microdissection of neuronal populations within the striatum of knock-in mouse models of HD (Hdh6/Q72 and Hdh4/Q80) demonstrated greater HTT CAG repeat expansion in a pan-neuronal (NeuN-positive) population compared to a nitric oxide synthase (NOS)-positive subpopulation of interneuron’s [14]. The gene discussed is RBFOX3; the disease is Huntington disease.