(A) The total number of osteocytes in bone, as determined by the number of osteocytes staining for DAPI normalized by bone area, in trabecular bone of 5 pediatric healthy controls, 12 pediatric pre-dialysis CKD patients, and 10 pediatric dialysis patients not receiving active vitamin D sterol therapy. (B) The relationship between numbers of FGF23-expressing osteocytes expressed as a percentage of total, DAPI-positive, osteocytes (X axis) (FGF23-expressing osteocytes/osteocyte number) and the number of FGF23-expressing osteocytes per trabecular bone area (Y axis) (FGF23-expressing osteocytes/B.Ar). Closed (black) circles show represent healthy controls; open circles represent pre-dialysis CKD patients; closed grey circles represent dialysis patients.