Many studies have also shown that the concentration of carcinoembryonic antigen (CEA), known as a marker of malignant transformation and chronic inflammation, is increased in a variety of cancers: e.g. carcinoma of pancreas [7]; uterine cancer [8]; cancers of the lung [9] and breast [10]; and among heavy smokers [11,12]. This evidence concerns the gene CEACAM5 and cancer.