The PERFUME (PERoxisome Formation, Function, MEtabolism) program is an interdisciplinary and intersectoral ITN providing state-of-the-art research training at the interface of medicine, plant and fungal biology. The PERFUME S&T specifically aims at unraveling the principles of peroxisome biology.Peroxisomes have been discovered relatively recently (in 1954). Consequently, the level of understanding of their biology is relatively weak compared to the knowledge of other organelles. Despite their modest appearance, they are crucially important for cell vitality. Peroxisomes ubiquitously occur in eukaryotes, display an unprecedented versatility of functions and are essential in man. Recent findings indicate that improper functioning of peroxisomes contributes to ageing and age-related diseases. However, there are still major gaps in our current knowledge of peroxisome biology. PERFUME aims to fill these gaps by focusing on i) the identification of novel peroxisome functions, ii) in-depth understanding of the compartmentalization of functions in peroxisomes and iii) unraveling the principles of peroxisome proliferation.Enhancing knowledge on these three themes is relevant for medicine, agriculture and biotechnology and demands directed analyses, which require the combined expertise from different disciplines and sectors that cut across historically separated fields. PERFUME brings together such a team comprising of top scientists from the fields of cell biology, biochemistry, genomics, proteomics, metabolomics, mathematical modeling, bioinformatics and protein structure analysis. Together, PERFUME shows maximal complementarity and synergy to warrant optimal training facilities for the participating students.