Complex human brain tissue has been successfully developed in a three-dimensional culture system established by scientists at the renowned Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences (OeAW). The method described in the current issue of NATURE allows pluripotent stem cells to develop into cerebral organoids – or "mini brains" – that consist of several discrete brain regions. Instead of using so-called patterning growth factors to achieve this, the IMBA scientists fine-tuned growth conditions and provided a conducive environment. As a result, intrinsic cues from the stem cells guided the development towards different interdependent brain tissues. Using the "mini brains", the scientists were also able to model the development of a human neuronal disorder and identify its origin – opening up routes to long hoped-for model systems of the human brain.