In view of the present and previous observations, the following sequence of events may lead to vascular calcification: Hyperphosphatemia leads to down-regulation of nuclear APEX1, which is in turn followed by up-regulation of CYP11B2, MR activation, MR-dependent up-regulation of PIT1 and subsequent triggering of osteogenic transformation. Here, SLC20A1 is linked to hyperphosphatemia.