Today´s powerful new tools enable researchers to construct novel experiments in a wide range of fields—from basic biomedical research to biotechnology and medicine—allowing them to edit genomes at sites of their choosing. Using most recent technologies in genome engineering, it is now possible to create knock-in, knock-outs and mutations of any gene in any cell line or organism with high efficiency. This approach allows the perturbation of biological systems at the genomic as well as the proteomic level. In silico analysis provides a good approximation of molecular structure in relation to function, and is always used to predict and enhance the success of genome editing technologies. The combination of these approaches is often used in gene therapy as well as in synthetic biology applications.