evidence: A Facebook post claims "Vitamin B17 is banned because it kills cancer cells" and says the substance can be found in apricot seeds. Vitamin B17 is a common name for a substance called amygdalin which indeed is found in apricots, as well as raw nuts and beans. A synthetic form of the substance, called Laetrile, has been marketed unofficially as a cancer treatment since the middle of the 20th century. [...] Does it kill cancer cells?