Does the human brain have an Achilles heel that ultimately leads to Autism? With a revolutionizing novel system that combines brain organoid technology and intricate genetics, researchers can now comprehensively test the effect of multiple mutations in parallel and at a single-cell level within human brain organoids. This technology, developed by researchers from the Knoblich group at the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences and the Treutlein group at ETH Zurich, permits the identification of vulnerable cell types and gene regulatory networks that underlie autism spectrum disorders. The results were published on September 13 in Nature.