There are a multitude of different methods to intervene in the genetic makeup of living beings in an undirected or directed manner. Currently, the CRISPR/Cas system, molecular gene scissors, are causing a sensation, as they make it possible to specifically edit genetic information. There is a controversial discussion as to whether organisms treated with this method must be considered genetically modified, as the modification cannot be distinguished from natural mutations. While gene editing using the CRISPR/Cas system mainly raises hopes for, for example, disease therapy or animal and plant breeding, there are also controversial further developments, such as the gene drive.