In this regard, etrasimod is an oral, selective S1P1, S1P4, and S1P5 receptor modulator in development for the treatment of immune- and inflammatory-mediated diseases; a phase 2 RCT study is currently being conducted to determine whether oral etrasimod is a safe and effective treatment for active eosinophilic esophagitis (EoE) in adult participants (NCT04682639). This evidence concerns the gene S1PR4 and eosinophilic esophagitis.