EphrinB2-Fc or EphB4-Fc affects bone parameters in nonmyelomatous bones. Hosts were treated with Fc, ephrinB2-Fc, or EphB4-Fc (5 mice/group) for 4 weeks using Alzet pumps that released 0.11 μg/hr of each compound directly into the implanted bones. (A-B) Numbers of osteoclasts (A) and osteoblasts (B) in implanted bones. EphrinB2-Fc increased numbers of osteoclasts and osteoblasts, whereas EphB4-Fc reduced osteoclast numbers but had no effect on osteoblast numbers. (C) Changes in histomorphometric parameters of implanted bones. Note increased levels of BV/TV, Tb.Th, and Tb.N by ephrinB2-Fc and EphB4-Fc.