VEGFA and cancer: The use of the anti-S1P mAb as a research tool has provided strong evidence that S1P has several mechanisms of action in promoting cancer, including: (i) direct effects of S1P on tumour-cell growth and metastatic potential, (ii) direct angiogenic effects on ECs in their tumour angiogenesis roles and (iii) indirect angiogenic effects of S1P in stimulating the release and action of other proangiogenic growth factors such as VEGF (Figure 2).