ISG20 and Huntington disease: We did not observe any increased expression levels of IFITM3, IRF1, IFIT2, and ISG20 upon type-I (IFNα2, IFNβ), -II (IFNγ) and -III (IFNλ1, IFNλ3) IFN stimulation in NK cells from HD and patients with chronic viral infections (Figures 3A, S4E, and S5A).