CEACAM5 and carcinoma: MEDI-565, also known as MT111, is composed of a human single-chain antibody recognising carcinoembryonic antigen (CEA, CD66e and CEACAM5), which is frequently expressed in carcinomas of the lung, pancreas, stomach, ovary, uterus, breast, colon and rectum (Hammarstrom, 1999), and a de-immunised single-chain antibody specific for CD3, which is connected by a short flexible linker sequence (Lutterbuese et al, 2009).