Gene therapy involves inserting genes into cells to treat disease, while stem cell therapy uses stem cells that can differentiate into other cell types. There are two types of gene therapy: germline modifies sperm or eggs and changes are inheritable, while somatic modifies patient's somatic cells and changes are not inheritable. Stem cell therapy currently uses adult stem cells from bone marrow or blood to treat cancers and blood disorders, and may potentially treat many other conditions. Both therapies aim to cure genetic disorders but also face scientific, ethical, and financial challenges.