4-Antibody AG is a Swiss biotechnology company concentrating on the development and optimization of human therapeutic antibodies by means of a new patented technology platform. This technology is based on a defined long-term in vitro tissue culture system for primary mouse precursor (preB) lymphocytes. These preB cells maintain their potential to develop into mature B lymphocytes and also into antibody secreting plasma cells. The company was founded in December 2002 as a spin off of the University of Basel. Today 4-Antibody has got 43 employees who work at the headquarters in Basel and at subsidiaries in Jena and Germany. At the premises of Jena so-called antibody libraries are being generated which help to efficiently develop new therapeutic antibodies.