MBTPS1 and ischemic stroke: The expression of S1PR2 protein decreased to the lowest level on the 7th day after MCAO modeling, with no significant difference compared with the control group (P > 0.05), which was consistent with the research of Matsumoto et al. (2020) [16], who deemed that the decreased S1P level was significantly correlated with the death of nerve cells in ischemic stroke.