It has been reported that the concentration of intracellular Ca2+ is higher in the osteosarcoma cell line MG-63 than the normal osteoblast line hFOB1.19, and activation of calcium-sensing receptor (CaSR) promotes osteosarcoma cell proliferation by upregulating phosphorylation of ERK1/2, PI3K and AKT 35. The gene discussed is MAPK3; the disease is osteosarcoma.