Osteoclast number, surfaces, and eroded surfaces in trabecular bones of sham operated ldlr−/− high fat fed mice, ldlr−/− high fat fed CKD mice (CKD V), and ldlr−/− high fat fed CKD mice treated with RAP-011, an ActRIIA ligand trap, (CKD R). CKD increased and RAP-011 treatment reversed the increase in osteoclast numbers, surfaces and eroded surfaces. (Reproduced with permission from Sugatani et al., Kid Int 91: 86–95, 2107).