SIK1 and hypophosphatemia: Nonetheless, the absence of overt hypophosphatemia or hyperphosphaturia (despite the caveat that our urine phosphate measurements were performed on “spot” samples rather than 24-hour urine collections) in such mice suggests that PTH-induced urinary phosphate excretion may also occur via a SIK-independent pathway, a model further supported by the lack of effects of SIK inhibitors on Npt2a localization and phosphate uptake in vitro (Supplemental Figure 8).