In conclusion, at the periphery, PGD2 is an established inflammatory mediator (Mohri et al, 2007), and its effects include enhancing vascular permeability (Flower et al, 1976), modulating chemotaxis (Hirai et al, 2001), antigen presentation (Hervé et al, 2003), vasodilatation, bronchoconstriction, platelet aggregation, glycogenolysis, allergic reaction, and intraocular pressure (Ahmad et al, 2019), as well as resolving peripheral nerve injury (Forese et al, 2020). This evidence concerns the gene PTGDS and peripheral nerve injury.