S1PR2 and retinopathy of prematurity: In oxygen‐induced retinopathy (OIR), a mouse model that mimics ROP and other proliferative retinopathies (Smith et al, 1994), sphingosine kinase‐2 gene (Sphk2), and S1pr2 KO mice (Skoura et al, 2007; Eresch et al, 2018), or mice treated with a blocking antibody against S1P (Xie et al, 2009) were protected from pathological neovascularization.