Discovery of new markers or therapeutic targets for the cells related to several diseases has been one of the most exciting fields in the life science. A lot of researches in this field are under way using proteomics and functional genomics tools. However, there have been no technical breakthroughs to investigate membraneous proteins on the cell surface. We plan to identify new markers or therapeutic targets using phage display technology where antibody libraries are displayed on the surface of bacteriophage. In the future, we plan to develop efficacious diagnostic tools and therapeutic antibodies for various human diseases.