CTSK and chronic kidney disease: Higher mRNA expression of osteoclast-related markers c-Fos, NFATc1, TRAP, cathepsin K, and carbonic anhydrase II in RAW 264.7 cells treated with both RANKL and MSU were significantly suppressed by CKD-WID treatment, similarly with the anti-osteoclastic effect of the calcineurin inhibitors cyclosporin A or FK506 (Figure 4D).