Dear Family, friends and colleagues, I am still shocked about the tragic death of Arren, too young leaving a gap not to be filled. Arren was the person who inspired myself most during the last years. He brought me and my group into his field of synthetic biology, I would never have touched without him. The work initiated by him opened my eyes for completely new directions and thoughts. He was not only inspiring, but always friendly and supportive. I will truly miss you. Sincerely, Martin Hagemann