Designing a gene therapy that spreads a specific gene mutation uncontrollably is unethical and extremely dangerous and should never be implemented for the following reasons: From an ethical perspective, this would cause unpredictable and incalculable harm to the human population, could lead to confusion in the gene pool, and have irreparable negative impacts on future generations. From a scientific and safety perspective, this uncontrolled gene spread cannot accurately target cells and tissues, can cause widespread off-target effects, can seriously damage normal physiological functions, cause a variety of unpredictable diseases and health problems, and may even lead to catastrophic consequences. Gene therapy should be used to treat diseases and improve health, follow strict ethical norms and scientific guidelines, and aim to benefit patients, not create harm and chaos. Therefore, there is no such a harmful gene therapy and it should not be designed.