GNAS and cancer: We initially screened a panel of imprinted genes composed of GNAS, GRB10, SNRPN, IGF2, and IGF2R using our Quantitative Chromogenic Imprinted Gene In Situ Hybridization (QCIGISH) method by evaluating the aberrant expression of imprinting loci in a variety of cancer tissue samples, and distinguishing the imprinting differences of normal and benign cases from cancerous tissues.