Anticancer snake venom

Snake venom contains tons of useful molecules that can be used to fight cancer, explains The Economist.  The first example goes over eristostatin, derived from the Asian sand viper, nature has evolved as an anti-coagulant:

Eristostatin’s day job is to stop victims’ blood clotting and thus plugging up damaged blood vessels after a bite. By increasing blood loss, it weakens victims. The molecule does this by glomming onto cellular fragments called platelets that are crucial to the process of clotting, thus disabling them. Dr Hailey hopes to make use of this tendency to encourage the immune system to attack melanoma cells. His idea requires eristostatin to be as attracted to cancer cells as it is to platelets.

Eristostatin goes one further and attracts T-lymphocytes, immune system cells that attack cells they're targeted to.  Hacking Harnessing the immune system to fight cancer is a clever idea, and one that's been bounced around before.