The promising preclinical results of S1PR inhibitor Fingolimod also creates possibilities for the use of other more selective S1PR inhibitors, such as Ponesimod (acts via S1PR1), Siponimod (acts via S1PR1 and S1PR5), and Ozanimod (acts via S1PR1 and S1PR5) in AD (Figure 2), especially since Fingolimod targets all S1P receptors (except S1PR2), creating potential harmful side effects (147, 148). This evidence concerns the gene S1PR5 and Alzheimer disease.