The platelet-activating factor (PAF) receptor (PTAFR) is a G protein coupled receptor that signals through multiple pathways and mediates several cellular responses including cell motility, smooth muscle contraction, and releases of cytokine and leukotriene (Stafforini et al., 2003). In humans, various diseases have been associated with PAF, such as allergic asthma, endotoxic shock, atherosclerosis and psoriasis.