Cancer has a high morbidity and a very high mortality, being the most common cause of death worldwide. Breast cancer is the second most common cancer overall,that represents about 12% of all new cancer cases and 25% of all cancers in women. Bioinformatics is an essential tool in target discovery and the in silico analysis is an integral part of it, facilitating the selection of the most important targets for a disease under study. The input of biochemistry to pharmacology has grown. Molecular pharmacology puts more emphasis on the mode of action of drugs, albeit it becomes clear that the activities of most drugs are not confined to one single mode of action. Studies in single cells become more and more popular, however, they do not cover the complexity of a whole organism. Therefore, the new requirements of the health authorities on safety pharmacology put emphasis on experiments in whole anesthetized animals. Therefore combined in-silico, in-vitro and in-vivo studies are an important tool for research in breast cancer metastasis.