GGPS1 (geranylgeranyl diphosphate synthase 1) is a key enzyme in isoprenoid biosynthesis that catalyzes the formation of geranylgeranyl diphosphate (GGPP), an essential precursor for protein geranylgeranylation and carotenoid synthesis 1. The enzyme displays high conservation between mouse and human (94% amino acid identity) and functions by converting isopentenyl diphosphate and farnesyl diphosphate into GGPP 1. GGPS1 operates through interactions with other proteins, including ENKD1, which modulates its enzymatic activity and influences downstream signaling pathways involving RAC1 2. Clinically, biallelic pathogenic variants in GGPS1 cause a rare autosomal recessive muscular dystrophy syndrome that may include hearing loss and ovarian insufficiency, though hearing loss occurs in only 46% of patients 3. The phenotypic spectrum has recently expanded to include hepatic involvement 4. In cancer biology, elevated GGPS1 expression correlates with chemoresistance in small cell lung cancer through the GGPS1-RAB7A-autophagy axis and predicts poor survival outcomes 56. Pan-cancer analyses reveal GGPS1 upregulation across multiple cancer types, particularly breast, liver, and lung cancers, suggesting its role in tumorigenesis 7. Therapeutically, statins targeting the mevalonate-GGPP pathway show promise in overcoming chemoresistance 5.