CST3 and hypophosphatemia: Finally, we could not draw major conclusion on renal safety of the regimen, as we only had available creatinine evaluation after the switch, without data on other parameters of renal function such as or cystatin C values, albuminuria, or signs of proximal renal tubular impairment (low molecular weight proteinuria, hypophosphatemia/hyperphosphaturia, normoglycemic glycosuria, and hypouricemia/hyperuricuria).