The Chinese team has developed a new gene editing system that produces more focused changes and fewer mistakes, using it to develop a therapy for a disease related to that of the same name: β-Thalassaemia. The CRISPR/Cas9 system uses specially structured RNAs (guide RNAs) that can base-pair with a targeted sequence to cut the DNA nearby, which is effective when the guide RNA can aligns with a DNA virus. However, small deletions can be caused by this process, which are often caused by DNA repair systems. The new system uses different types of DNA editing techniques to insert modifications into the genome, but this process is error-prone.