ICMT and progeroid syndrome: These results are important because progerin rather than prelamin A causes progeria in LmnaG609G mice, and because homozygous LmnaG609G/G609G mice exhibit a vascular phenotype, which are prominent in children with HGPS, but absent in Zmpste24-deficient mice used in earlier studies (Ibrahim et al., 2013)—and Icmt inactivation markedly improved this phenotype.