PAX5 and chronic kidney disease: Bone turnover markers (ALP, bone-specific alkaline phosphatase [BSAP], P1NP, DKK-1, tartrate-resistant acid phosphatase 5b [TRAP5b]) are decreased; however it should be noted that only BSAP, intact P1NP, and TRAP5b are reliable in patients with CKD because they are not renally cleared.