MBTPS1 and Alzheimer disease: Notably, the S1P beneficial effect can be sustained over time by sphingosine kinase‐1 overexpression, thus counteracting the down‐regulation of the S1P signalling induced by Aβ42O. Our findings disclose underlying mechanisms of S1P neuronal protection against harmful Aβ42O, suggesting that S1P and its signalling axis can be considered promising targets for therapeutic approaches for AD.