Gene targeting is a technique used in genetics to modify specific genes within an organism's DNA. This process allows scientists to either knock out a gene, rendering it inactive, or introduce a new gene with desired traits. By using methods like CRISPR or homologous recombination, researchers can create precise changes in the genome, which can help in studying gene functions and developing treatments for genetic disorders. This approach is particularly valuable in creating animal models for human diseases, such as cancer or diabetes. By understanding how specific genes contribute to these conditions, scientists can develop targeted therapies and improve our knowledge of genetic influences on health.