S1PR2 and Hepatic fibrosis: S1P was first shown to stimulate rat hepatic stellate cell proliferation, suggesting that S1P could be a pro-fibrotic factor in the liver48; several studies clearly showed that this pro-fibrotic effect is regulated thorough the S1P receptors S1P1, S1P2, and S1P3 on hepatic stellate cells46,49–52, suggesting that depletion of S1P by SPHK inhibitors could be effective for liver fibrosis.