The riddle of the Sphinx: why sphingosine-1-phosphate may help define molecular mechanisms underlying risk stratification for serious COVID-19 infections.

The sphingosine-1-phosphate (S1P) is a lysophospholipid signaling molecule with important functions in many physiological and pathological conditions, including viral infection. In this issue of EMBO Molecular Medicine, Marfia et al present a risk stratification based on S1P serum level as a novel prognostic indicator for COVID-19 severity.