PTGDR2

Prostaglandin D2 Receptor 2 (PTGDR2), commonly known as CRTH2, is a G protein-coupled receptor (GPCR) that binds to prostaglandin D2 (PGD2). Upon ligand interaction, it activates Gαi signaling, triggering chemotaxis of Th2 lymphocytes, eosinophils, and basophils, and promoting release of pro-inflammatory cytokines like IL-4 and IL-13.
PTGDR2 is implicated in allergic disorders including asthma, allergic rhinitis, and atopic dermatitis. Selective antagonists targeting this receptor are under development: fevipiprant, a CRTH2 blocker, has advanced to phase III trials for severe asthma, aiming to reduce airway inflammation and hyperresponsiveness by inhibiting the PGD2-CRTH2 axis.