DNA repair using nanobots. Computer artwork depicting the possibility of using robots at an atomic scale (nanobots) to repair damaged DNA (deoxyribonucleic acid), the body's genetic code. When DNA becomes damaged it can, amongst other things, lose the ability to stop its own replication. This leads to cells multiplying uncontrollably, forming tumours. This is the cause of cancer. Scientists are trying to develop machines that can work at a molecular level to fix DNA before this becomes a problem.