CRISPR/Cas9 technology has become very popular in the last 5 years and has profoundly changed our way to do genetically engineered animals. I will present the latest development in genome editing at PHENOMIN-ICS. From the easy high throughput KO production for the International Mouse Phenotyping consortium (https://www.mousephenotype.org/) to the generation of complex models, different examples (from simple point mutations to conditional knock-outs) will be shown and discussed. The benefits of oocyte electroporation, which is much more efficient than microinjection and has allowed to reduce the number of animal needed for all experiments, will be presented. The pertinence of the use of CRISPR base editing (cytidine deaminase) for specific mutations was assessed and the results of our pilot experiment will be shown. And finally, the advantages of the use of embryonic stem cells (with the help of CRISPR) for genetic modifications larger than small knock-ins will be presented.