Platelet activating factor (PAF) is a low molecular weight, ether-linked phospholipid originally identified as a soluble factor, released from sensitized rabbit basophils during IgE anaphylaxis, that was capable of aggregating rabbit platelets [1, 2]. Cellular sources of PAF subsequently identified include neutrophil [3–8] and eosinophil granulocytes [9, 10], mononuclear phagocytes [4, 5, 11–15], mast cells [16, 17], platelets [18, 19], natural killer cells [20], fibroblasts [21], vascular endothelium [22–24], epithelial cells [25–27] and glomerular mesangial cells [28], as well as brain cells [29, 30], and spermatozoa [31], many of which generate PAF in response to a wide variety of stimuli [32].