The function of Ensembl gene identifier ENSG00000169403 (PTAFR, platelet activating factor receptor) is as follows. Receptor for platelet activating factor, a chemotactic phospholipid mediator that possesses potent inflammatory, smooth-muscle contractile and hypotensive activity. Seems to mediate its action via a G protein that activates a phosphatidylinositol-calcium second messenger system. {ECO:0000269|PubMed:1281995, ECO:0000269|PubMed:1374385, ECO:0000269|PubMed:1656963, ECO:0000269|PubMed:1657923}.