This biochemical cascade triggered by FCM infusion has therefore been termed the “6H-syndrome: (1) high FGF23, (2) hyperphosphaturia, (3) hypophosphatemia, (4) hypovitaminosis D, (5) hypocalcemia, and (6) secondary hyperparathyroidism” [2]. The gene discussed is FGF23; the disease is hypophosphatemia.