The toxin found in the Death Cap mushroom may be able to kill cancer cells. Researchers/scientists based in Germany took the toxin, known as a-amanitin and attached it to an antibody.
Source: https://commons.wikimedia.org/wiki/File:A-amanitin.png
These antibodies allowed for the toxin to get into the body without being detected by the immune system. They tested this compound through mice with multiple different types cancer. In 9/10 of the mice cancer cell growth was slowed and reduced.
This is amazing news hearing that this compound can basically kill cancer cells in mice, but can it work with humans? It would be a huge leap in medicine and science if the compound was regulated and safely tested on humans. If we were able to reach this equilibrium, many lives would be prolonged and even saved.
Source: https://www.the-scientist.com/the-nutshell/poisonous-shrooms-battle-cancer-41151