In 2020, the Nobel Prize in Chemistry was awarded to American molecular biologist Jennifer Doudna and her French colleague Emmanuelle Charpentier for their fundamental research on CRISPR, an ingenious bacterial immune system. Studies into the working mechanism of CRISPR led to many Eureka moments. Through smart biotechnological engineering, CRISPR became suitable for applications in 'DNA surgery': the targeted editing of the genetic code. Here, we discuss emerging medical CRISPR applications for the treatment of human genetic disorders, including in vivo therapy. This Nobel Prize-winning discovery is powerful, adaptable and accurate, and clinical trials are being launched at an amazing pace. However, extensive research is needed on safe clinical use and possible side effects of CRISPR. In addition, the regulations on market authorization and reimbursement are not yet tailored to this very personal and potentially expensive therapy. Whereas challenges remain, CRISPR gene therapy will continue to rapidly mature as a clinical reality.