Moreover, SphK1, but not SphK2, expression levels were demonstrated to be correlated with microvascular density (MVD) of ovarian cancer tissue; the angiogenic potential and the angiogenic factor secretion of ovarian cancer cells could be mitigated by SphK1 blockage and were shown to be restored by adding S1P [80]. Here, SPHK1 is linked to ovarian carcinoma.