(a and b) Serum osteocalcin (OCN), (c and d) serum CTX, and (e and f) serum RANKL/OPG for WT and Nmp4−/− mice (24 weeks of age). (b, d, and f) We compared the anabolic therapies PTH + RAL, PTH + ZOL, and PTH with each other and with VEH using the three serum parameters as endpoints. (g) We compared VEH with RAL monotherapy using RANKL/OPG as the endpoint. Statistical analyses were performed using two-way analyses of variance, setting genotype and treatment as the independent variables. Statistical significance was set at P ≤ 0.05. The data represent mean ± standard deviation, n = 6 to 7 (OCN, CTX, RANKL/OPG). See text for explanation of results.