to treat cancer. Gene therapy introduces foreign genetic sequences to diseased cells in order to change the expression of these cancerous cells that are functioning with severely damaged genomes. Cancer cells do not behave like normal cells, so the methods for ridding the body of these cells are more complicated. Manipulation of the pathways controlled by certain genes and their regulators are a large branch of cancer research. See also Oncology Molecular medicine References Medicinal chemistry Oncology Interdisciplinary subfields of medicine