SPHK1 and neoplasm: Western blotting for phosphorylated SPHK1 and ELISA for S1P further confirmed that S1P production was significantly increased in the tumor tissues of EL4-WSHFD mice (Fig. 3D-E), indicating that S1P could play a key role contributing to the malignant events such as proliferation and migration in the EL4-WSHFD mice.