Improved understanding of those mechanisms could potentially significantly decrease morbidity associated with bone disease of multiple myeloma, especially considering that Terzi Demirsoy et al. [49] found that patients with elevated FGF-23 levels had decreased overall survival, indicating that FGF-23 either does have a role in the pathogenesis of myeloma or that it could simply be a marker of more advanced disease. This evidence concerns the gene FGF23 and AL amyloidosis.