The document discusses using bacteriophages or phages as vectors to inject genetically engineered DNA into human cells to cure and prevent diseases. Phages can be engineered to carry DNA that codes for the destruction of diseases or creation of resistant cells. The process involves identifying the medical condition, obtaining the proper DNA, placing it in phages, infecting patients with the phages, and allowing the DNA to spread through the body's natural processes. Phage therapy could potentially treat many bacterial infections and genetic disorders with few side effects due to phages' specificity.