MBTPS1 and psoriasis: This review highlights the importance of the S1P-S1PR signaling system in the inflammatory process, describes the specific mechanisms by which S1P and its signaling are involved in the pathogenesis of psoriasis, describes the available clinical/preclinical evidence for targeting S1P-S1PR in psoriasis, and identifies S1PR modifiers (e.g., S1P-S1PR).