If a patient reports symptoms related to an increase in volume of the pancreatic macrocysts (imaging based) and drainage or aspiration is performed, the quality of the fluid must be thoroughly examined for amylase, proteins, carcinoembryonic antigen (CEA) levels, and serum CA19-9 in order to exclude the possibility of a malignant mucin-producing neoplasm [4, 8, 10]. The gene discussed is CEACAM5; the disease is cancer.