Laboratory Investigations The area of molecular biology is rapidly developing with respect to biological knowledge as well as technical analytical methods. Thus, it is not possible to predict upfront which genes may be of particular interest in 5 years from know; neither is it possible to foresee completely which laboratory methods will be available. Our aim is to explore potential genetic alterations explaining the mechanisms of drug resistance. While it is not possible to predict in detail, the aim of the study and all analysis to be conducted should aim at this major goal.