When the body is damaged trophoblast {or healing} cells are dispatched in large numbers. These cells carry a negative charge as does the immune system. Because of this trophoblasts are protected. Once the healing is done the auxiliary trophoblasts must be destroyed. The benzaldahyde and hydrocyanic acid within the Amygdalin carries out this function. If you lack vitamin B17 healing cells metastasize unchecked. That's what cancer is.