How do cancer cells evade the immune system, growing undetected until they're discovered as a tumor? Biotechnology company TapImmune believes it has the answer to this fundamental question. The Bellevue, Wash.-based company is developing a line of therapeutics and vaccines designed to prevent cancer and infectious diseases from growing out of control. TapImmune's pipeline is based around TAP, or transporters associated with antigen processing. TAP is a critical peptide that moves cancer proteins to the surface of cells, where they are recognized by the immune system. When cancer grows, it decreases TAP's efficacy, thereby decreasing the presentation of cancer antigens on the surface of cells. TapImmune's products are formulated to restore TAP to cancer cells that are deficient, allowing the immune system to recognize and attack the cancer cells before they can metastasize. TAP is expressed in all cells and is applicable to a wide variety of cancers and pathogens. Clinical studies have shown a strong correlation between loss of TAP expression and patient survival. TapImmune's first targets are melanoma and non-small cell lung cancer. The company is also developing a vaccine for smallpox. TapImmune's smallpox vaccine may have applications as an adjuvant therapy against many other infectious diseases. Related video: Denis Corin, President of TapImmune, discusses the company's technology platform at the 2010 OneMedForum.