NMNAT2 cKO mice exhibited evident hindlimb clasping (Fig. 1B, Fig. 1-S1F, and supplementary video), ataxia and forelimb circling phenotypes (10 out of 10 mice examined), reflecting motor behavioral deficits similar to those observed in many neurodegenerative mouse models [41–43]. Here, NMNAT2 is linked to cerebellar ataxia.