Etv1C/C mice, however, are viable and fertile and do not present any overt abnormalities, although other Etv1-null mutant strains (Etv1ETS/ETS and Etv1nlslacZ/nlslacZ mice; for their allele structures, see Extended Data Fig. 2-1A) exhibit limb ataxia or abnormal postures attributable to defects in proprioceptive function and die three to five weeks after birth (Arber et al., 2000; Patel et al., 2003). Here, ETV1 is linked to Limb ataxia.