Conventional serum tumour markers, such as carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC), have been used as convenient diagnostic assays (Kosugi et al, 2004; Mroczko et al, 2008) for early detection and monitoring tumour dynamics of ESCC. The gene discussed is CEACAM5; the disease is esophageal squamous cell carcinoma.