The vertebrate nervous system consists of a multitude of different cell types each with a unique identity and function. We are interested in how this cellular diversity is generated during development and how the established neuronal identity is subsequently maintained. A particular focus of our research is on how alternative gene programs are permanently silenced. In addition to exploring fundamental mechanisms of neuronal differentiation and identity, our research also aims to understand how errors in these processes can influence tumor formation and cellular degeneration in the nervous system. We mainly utilize different mouse models both to investigate the mechanisms underlying regulation of neuronal identity and nervous system tumor formation.