Second, anti-sclerostin antibodies (romosozumab) have also been successfully developed for the treatment of osteoporosis (108), based on the observation that loss-of-function mutations in sclerostin (a bone morphogenetic protein antagonist) were responsible for massive accumulation of bone in the rare recessive disorder, sclerosteosis (OMIM 269500). This evidence concerns the gene SOST and osteoporosis.