We were the first to suggest that nephrocalcinosis might be an osteogenic-like cell-driven process [6,7], and our previous studies provided the first evidence of human renal cells undergoing calcification under certain circumstances, such as glial cell-derived neurotrophic factor (GDNF) gene down-regulation, in much the same way as in vascular calcification [8]. The gene discussed is GDNF; the disease is nephrocalcinosis.