CASR and medullary thyroid gland carcinoma: Although most research has focused on intracellular calcium mobilization in HEK293 cells heterologously expressing the CaSR, CaSR-induced [Ca2+]i oscillations have also been found in cells with endogenously expressed CaSR, for instance in parathyroid cells [31], bovine anterior pituitary cells [32], opossum kidney (OK) cells [33] and medullary thyroid carcinoma cells [34].