ZMPSTE24 and Hutchinson-Gilford progeria syndrome: Targets for the type I prenyl protease Ste24p include the yeast a-factor mating type pheromone and mammalian A-type lamin (Chen et al. 1997; Boyartchuk and Rine 1998; Corrigan et al. 2005), but additional targets are suggested because homozygous mutations in human Zmpste24 cause a perinatal lethal disease called restrictive dermopathy, with phenotypic symptoms strongly resembling characteristics of HGPS (Navarro et al. 2005).