S1PR1 and ovarian cancer: It can thus be assumed that either S1P or S1PR1/3 are responsible for the production of the angiogenic factor and the angiogenic potential of ovarian cancer: S1P and S1PR1/3 antagonists (i.e., SphKI-II and VPC23019, respectively) could block, or at least attenuate, the pro-angiogenic effects of both of them [80].