FAS and systemic lupus erythematosus: Xin et al. found that S1PR1 was downregulated in the PBMCs of patients with SLE and the spleen cells of lupus mice, and miR-155(−/−) Fas(lpr/lpr) mice inhibited the occurrence and development of SLE by regulating the target S1PR1 gene [32], indicating that S1PR1 is involved in the pathogenesis of SLE.