In our project, we aim to develop cancer specific monoclonal antibodies (mAbs) using our original technologies, the CasMab method. We will immediately transfer the developed mAbs to pharmaceutical companies. Antibody drugs have been used for cancer therapy; however, the toxicity against normal cells are always worried when non-cancer specific mAbs are used in clinical studies. Because cancer-specific antigens are known to be limited, it might be difficult to develop mAbs for novel molecular targets. For the conventional production of mAbs, synthetic peptides or recombinant proteins using E. coli and mammalian cells such as CHO or HEK-293T. In this study, we will use cancer cell lines, which could produce cancer-specific glycans. We plan to combine the CasMab method with GpMab method to develop anti-glycopeptide mAbs and cell-based immunization and screening (CBIS) method to produce mAbs using target-overexpressed cell lines. Recently, the antibody drug conjugate (ADC), the radioimmunotherapy (RIT), and the chimeric antigen receptor T (CAR-T) therapy have been developed for novel modalities of antibody therapies and immunotherapies. We also plan to utilize these technologies for our original cancer-specific mAbs. The final goal of this project is the development of cancer-specific antibody drugs or immunotherapies without side effects for refractory cancers such as mesotheliomas or brain tumors.