1. Someone who was born with a genetic disease by replacing non-functional gene with functional one.
2. When someone in their family has an operation, it's easy to get an organ from relative for patient's need.
3. It helps to keep genes going through generation.
4. It helps you to know who your family is.
5. It make we evolution to be Stronger and stronger generation by generation.
6. It can protect and solve a problem which from the inheritance, for example avoid having a child with people who have a disorder disease.