KLK5 and osteogenesis imperfecta: The other gene cluster was located in the network of “fibroblast” (top 30), which contains KLK5, KLK7, PRSS8, and SLC6A14. In addition, GGPS1, a member of the prenyltransferase family, which encodes an enzyme that catalyzes the synthesis of geranylgeranyl diphosphate from farnesyl diphosphate and isopentenyl diphosphate, was associated with osteogenesis imperfecta.