The 33-fold longer serum half-life of PTH-Fc compared with that of PTH (1–34) is beneficial for space medicine to reduce dosing frequency, yet more hypercalcemia was observed with PTH-Fc compared to PTH (1–34) in osteopenic ovariectomized mice and rats (Kostenuik et al., 2007). The gene discussed is PTH; the disease is Hypercalcemia.