G-protein coupled receptors (GPCRs) are a large family of transmembrane proteins responsible for the variety of signal  transduction events both vertebrates and invertebrates. These seven transmembrane domain molecules are directly involved in regulating of tick physiology underlying tick, development, behavior, host seeking, reproduction and feeding. One of the most interesting findings in Ixodes scapularis genome was definitely the discovery of expanded number of GPCRs comparing to other invertebrates. This expansion of specific GPCRs gene copies is likely directly reflecting the ticks ectopariasitic lifestyle involving the acute needs of the precise regulation of processes related to blood uptake, satieity, digestion, diuresis or egg development. Therefore investigation of these molecules has a strong potential to elucidate key aspects about parasitic tick lifestyles.