FGF23 and chronic kidney disease: Bone FGF23 expression correlated with parameters of skeletal mineralization; osteoid thickness inversely correlated with bone FGF23 expression (r = - 0.46, p<0.01) when all subjects (kidney transplant recipients, liver or heart transplant recipients, and non-transplant CKD patients) were considered together; similar relationships between osteoid thickness and bone FGF23 expression were observed when each subgroup was considered individually.