With CRISPR/Cas gene editing tools in hand, we are currently experiencing a new dimension in genetic engineering. But where should the journey lead? Should we treat diseases or better repair them genetically? Will the new genetic engineering, combined with modern reproductive biology, lead to designer babies? And: May we allow a liberalization of these techniques as citizen science? New methods can precisely alter the genetic material - and they leave no traces. This gene and genome surgery thrives on increasing knowledge about the mode of action of genes, those trait-giving regions in the genome. This knowledge is being applied in practice, particularly in the breeding of more resistant and higher-yielding crops. And what about us? The author shows that gene variants have long been associated not only with diseases, but also with nutritional preferences or intelligence. Therapeutic and optimization options are close at hand. What effect does the environment have on the expression of genetic material? Genes can be shaped during a person's lifetime by the environment, nutrition or experiences and thus passed on to their offspring in a modified form. So does society have a new form of long-term responsibility for (epi)genetic integrity? In this vividly and comprehensibly written book, the author explains the state of genetic engineering without assuming too much prior knowledge and invites an open dialogue on this ambivalent topic. Get your own idea of the fascinating yet intimidating possibilities of genetic engineering. Where do you stand on the issue? With the help of this book, you have the chance to form a differentiated opinion. This translation of the original German was done with the help of artificial intelligence (machine translation by the service DeepL.com), and subsequently revised by the author. Springer Nature works continuously to further the development of tools for book production and on the related technologies to support the authors.