MBTPS1 and fibrosis: Although there are reports that S1P participates in collagen deposition in an S1P receptor-independent manner (Xiu et al., 2015), the contribution of S1P receptors to the pro-fibrogenic effect of S1P was reported in vitro, in murine models of liver fibrosis (Schwalm et al., 2013; Takuwa et al., 2013) and in patients with advanced fibrosis (Sato et al., 2016).