A monoclonal antibody antagonist, Ab3-8, has been developed that recognizes the extracellular domain of ASCT2, reduces cellular glutamine import and Akt/ERK phosphorylation in SW1116 and HCT116 human CRC cell lines containing mutated KRAS, and inhibits the growth of tumor xenografts in mice (163). The gene discussed is KRAS; the disease is colorectal carcinoma.