The completion of the Human Genome Project enabled us to conduct comprehensive analysis of biological information for the first time. The department of systems biology and medicine was established in 2002, in order to organize a new comprehensive approach of biology and medicine. We are interested in elucidating the overlapping mechanisms regulating human systems using transcriptomics, protemics and genomics approaches. We have been accumulating a huge amount of gene expression profile data, and we opened a database for worldwide researchers. From these data, we picked up around 1000 disease target genes related to human cancer, atherosclerosis, metabolic syndrome and immune disorders, and we have been making monoclonal antibodies against these target proteins. We hope that these antibodies can be used for the diagnosis and therapy of these disorders.