Right behind cardiovascular diseases, cancer ranks second in causes of death in Austria. It can develop in any human tissue, is characterized by an abnormal cell growth and follows a multistage development which can be divided into three steps - initiation, promotion, progression. Healthy cells are in homoestatic balance between cell division, differentiation, and apoptosis. During cancer development, this balance is shifted towards proliferation, dedifferentiation and inhibition of apoptosis. Substance testing has to be conducted according to the 3 R - concept. According to the OECD -...