Medicine Which of the following Slatements is not true? A Parathyroid hormone-related protein is responsible for causing hypercalcemia in cancer patients B The unionized fraction of calcium in the plasma is an impoant determinant of PTH secretion C Mg2+ influences PTH secretion in the same direction as Ca2+ but is a less potent secretagogue D Ca2+influences PTH secretion by acting on a calcium sensor G-protein coupled receptor located in the parathyroid gland 💡 Explanation Which of the following Slatements is not true? ✓ Correct Answer: B. The unionized fraction of calcium in the plasma is an impoant determinant of PTH secretion