Gene switch. Conceptual computer artwork representing a gene switch, showing a switch (red) on one of the arms of a chromosome. Chromosomes, found in cell nuclei, contain the genetic material DNA (deoxyribonucleic acid). Genes are sections of the genetic code (contained in DNA) which perform a specific function and contain the instructions to produce proteins for a specific purpose. This function can be switched on or off (activated or repressed) by proteins that bind to DNA. Some gene therapies take advantage of this by switching certain genes on or off in order to treat a genetic disorder. Gene switching is also part of the normal cell biochemistry.