S1PR1 and myeloid sarcoma: S1P signaling is also implicated in controlling astrocyte functions that include gap junction formation (Rouach et al., 2006), migration (Mullershausen et al., 2007), cytokine production (Dusaban et al., 2017), and nitric oxide production (Colombo et al., 2014) via S1P1 and/or S1P3, all of which support S1P-mediated roles for astrocytes in EAE and MS.