All of the above effects can contribute to tumorigenicity and, in fact, ectopic expression in rat L6 myoblasts [16] or over-expression in human Caco2 colonocytes [10] of CEA and/or CEACAM6 prior to differentiation leads to a marked decrease in the latent period for tumor formation in nude mice. The gene discussed is CEACAM5; the disease is neoplasm.