Targeted therapies have revolutionised the treatment of cancer since they were first introduced. Amongst the first medications approved in Europe, was the breast cancer drug Herceptin, which was approved in 2000. Then, the drug Glivec, was initially introduced to treat a certain form of leukaemia, and approved in 2001. Targeted therapies specifically inhibit molecules within so-called signalling pathways that usually control cell growth, death and differentiation. If they are altered, for example falsely inactivated or activated, the cells may start growing in an uncontrolled manner.