S1PR1 and glioblastoma: Glioblastoma cells do express S1P receptors, mainly S1P1, S1P2, and S1P3, ref. [50] that promote cell proliferation, migration, and invasiveness [32,49] and S1P acts in different cell types, including glioma cells, also activating the PI3K/Akt pathway [51,52,53].