Ste24p homologues* in a diverse group of organisms, including Escherichia coli, S. pombe, Haemophilus influenzae mutants with altered phototropism, and Homo sapiens. HIV-PIs (protease inhibitors) inhibit ZMPSTE24, leading to an accumulation of farnesyl-prelamin A is the deleterious agent leading to the HGPS phenotype (Hutchinson-Gilford progeria syndrome) but they are associated with lipodystrophy and other side effects. Which encodes two nuclear envelope proteins lamin A and lamin C, or prelamin A the unprocessed toxic form of lamin A the processing enzyme of metallopotease ZMPSTE24 farnesylated form of prelamin A known as progerin, that ZMPSTE24 encodes. An enzyme necessary for the correct processing and maturation of lamin A an intermediate filament (IF) component of connective tissue synthesis (interacts with a broader repertoire of desmosomal-like junction components) by the secondary laminopathy gene ZMPSTE24 locus: 1p34; [§§], processing endoprotease–†, the posttranslational processing (FACE-1) of Ste24p carboxy terminal residues of farnesyl-CAAX protein (FTIs) types A or B patterns of lipodystrophy mutant prelamin A to form mature lamin A. Mutations in ZMPSTE24 may cause MAD (Mandibuloacral dysplasia) by affecting prelamin A processing. These phenotypes are largely rescued in Zmpste24-null/Lmna heterozygous, phenotypic and biochemical similarities with Zmpste24 -/- mice and progeroid features farnesyltransferase inhibitors (FTIs) reverse this cellular abnormality and may have beneficial effects in humans with progeria, generalized lipodystrophy.