In symptomatic HD patients and mouse models, the number of GABAergic parvalbumin (PV)-expressing interneurons is decreased and their dendritic arborization is greatly diminished (Reiner et al., 2013; Simmons et al., 2013; Paldino et al., 2017; Holley et al., 2019). The gene discussed is PVALB; the disease is Huntington disease.