The Department of Developmental Pathology is devoted to translational research, connecting basic molecular biology with medical sciences. Using modern molecular biology approaches, we address questions relating to genetic and epigenetic regulation in the field of stem cell biology. Here, we address the question, how pluripotency is regulated during early embryogenesis and during germ cell tumor development. We focus on early lineage specification and the biology of germ cells and germ cell tumors. Using CRISPR/Cas9 mediated gene editing, we generate animal models for genes involved in regulating proliferation and differentiation processes, to study effects in a physiologically relevant environment. Using germ cell tumor cell lines, we analyze the genetic and epigenetic regulation of the context-dependent cross-talk between tumor and stroma cells.