A comparative PET imaging study comparing 76Br-labeled anti-carcinoembryonic antigen mAb [76Br]Br-38S1, [18F]FDG and L-[methyl-11C]methionine ([11C]Met) in human colon carcinoma bearing rats showed that [76Br]Br-38S1 was the superior imaging agent, with higher tumor/tissue ratios [99,100]. The gene discussed is CEACAM5; the disease is neoplasm.