Soon, indium-111 scintigraphy imaging studies were translated to the clinic, which afforded high contrast images (Le Doussal et al., 1993; Peltier et al., 1993; Vuillez et al., 1997; Barbet et al., 1998), particularly in medullary thyroid carcinoma (MTC), a tumor that consistently expresses high levels of CEA. The gene discussed is CEACAM5; the disease is medullary thyroid gland carcinoma.