able to inhibit angiogenesis and tumor growth. S1PR1 is also involved in other types of cancer: fibrosarcoma cells migrate upon activation of S1PR1 by S1P via RAC1–CDC42 dependent pathway) and ovarian cancer cell invasion involves S1PR1 or S1PR3 and calcium mobilization. Multiple sclerosis S1PR1 is involved in multiple sclerosis. Fingolimod, a drug which internalizes the receptor, is approved as a disease modifying agent in MS. There are other Sphingosine-1-phosphate receptor modulators. Van Doorn et al. (2010) observed a strong increase in S1PR1 (and S1PR3) expression in hypertrophic astrocytes both in the active and inactive MS lesions from MS patients compared to the unaffected patients. Interactions S1PR1 has been shown to interact with 5-HT1A receptor, GNAI1, and GNAI3. See also Lysophospholipid receptor References External links G protein-coupled receptors Immune system