SPHK1 and thyroid cancer: S1P is known to stimulate cell proliferation and migration in human aortic endothelial cells [51], murine satellite cells [52], WiT49 cells [53], human thyroid cancer cells [54], and many other cell types and can be inhibited by SPHK I2 which is a selective inhibitor of SphK1 with anti-proliferative capacity [46].