S1PR1 and acute lymphoblastic leukemia: When we compared the S1P-induced migration rate (10 nM) of the various T-ALL cells as a function of the corresponding S1P1 gene expression level, we noticed that the numbers of migrating cells were higher for CEM cells and lower for MOLT-4 and JURKAT, suggesting that S1P1 mRNA expression is directly correlated with their migration capacity (S1 Fig).