Developmental Biology research aims to understand the events and signaling cues taking place during the development of living organisms and organs. Historically, Developmental Biology relied heavily on complex model organisms like clawed frogs, fruit flies or mice. Today, researchers interested in the development of organs increasingly utilize organoids. These are artificial three-dimensional model systems that can imitate the cellular composition and tissue architecture of organs while also being easier to maintain and to manipulate experimentally. In the symposium we will discuss the challenges related to this new approach and address some of the characterization possibilities of organoids