Chromos Molecular Systems wants you to part with that chromosome. This company is developing therapeutic products to fight diseases based on its ACE System (artificial chromosome expression) and REM (rapid expansion method) technologies. ACE System is the company's leading product candidate and carries genes to target cells where they can be expressed. In 2004 the company bought CellExSys from Targeted Genetics to gain new cell therapy technology and a pipeline of products that could treat infectious diseases and cancers. It also signed development agreements with Cambridge Antibody Technology, Centocor, and Pfizer.