Recently, human clinical trials involving FGF23-related hypophosphatemic diseases patients—X-linked hypophosphatemic rickets (XLHR) and Tumor-induced osteomalacia (TIO)—receiving a fully human recombinant IgG1 monoclonal antibody anti-FGF23 (burosumab) is ongoing (51). This evidence concerns the gene FGF23 and X-linked hypophosphatemic rickets.