In ovariectomized (OVX) mice, a model of postmenopausal osteoporosis (OVX plus three-injection model), it was observed that the serum TRAP overshoot persisted for a longer period after discontinuation of anti-RANKL antibody than in non-OVX mice (three-injection model; Fig. 5a, b). Here, ACP5 is linked to postmenopausal osteoporosis.