Alternative cancer treatment describes any cancer treatment or practice that is not part of the conventional standard of cancer care. These include special diets and exercises, chemicals, herbs, devices, and manual procedures. Most alternative cancer treatments do not have high-quality evidence supporting their use. Concerns have been raised about the safety of some of them. Some have even been found to be unsafe in certain settings. Despite this, many untested and disproven treatments are used around the world. Promoting or marketing such treatments is illegal in most of the developed world.