MUC5AC and neoplasm: Previously, tumour antigens were not easily identified, but currently identified antigens include glycoproteins and glycolipids (for example, gangliosides), developmental and over-expressed antigens (for example, CEA (carcinoembryonic antigen), gp75, MAGE, tyrosinase, melan-A, mucin [MUC]1), and mutated oncogenes (for example, p53, HER-2/neu, ras) [1].