Discovered and first isolated in 1966 in C. De Duve's laboratory, peroxisomes - organelles which are present in nearly all eukaryotic cells - are still not fully understood. More than 40 peroxisomal enzymes catalyzing a variety of reactions have been characterized. Moreover, peroxisomes can be regarded as toxicological indicators: several compounds, including hypolipemic drugs, plasticizers or pesticides trigger their proliferation. This proliferation may lead to hepatocarcinogenesis in rodents. Interest in peroxisomes stems not only fromtheir biology, but also because there is a deficiency...