Human disease associated with mutations in the RANKL gene is rare, although a novel mutation in the gene for transforming growth factor beta 1 (TGFβ1) and a missense change in TNFSF11 encoding RANKL may both contribute to the bone phenotype associated with Camurati-Engelmann disease [61]. This evidence concerns the gene TGFB1 and Camurati-Engelmann disease.