A variety of diseases affecting several systems have been linked to abnormalities in protein prenylation, such as diabetes, obesity, fatty liver disease, male infertility, chronic heart failure, and inflammatory bowel disease.305–307 Aberrant expression of GGPPS was observed in diabetes, fatty liver disease, male infertility and cardiac hypertrophy, which disrupted the balance of protein farnesylation and geranylgeranylation. Here, GGPS1 is linked to male infertility.