The molecular analysis of our structural constituents has provided important clues about disease pathogenesis and, at the same time, unravelled substantial interindividual differences leading to diverse phenotypes of a given disease. Sensing these differences as well as being aware of the stable molecular characteristics of a disease are the prerequisites of a promising therapy tailored to the needs of a particular patient. This type of "individualized", "personalized" or "stratified" medicine is now gaining broad entrance into different fields of medicine. We have therefore organized a symposium addressing the medical, but also the socioeconomic, legal and ethical aspects of this important topic. The symposium was held under the auspices of both the German and the Austrian National Academy of Sciences and took place on January 12-14, 2012 in Vienna, Austria.