What is "huachansu"

HuaChanSu (bufo bufo gargarizans) is a traditional Chinese medicine extracted from the skin of the Bufo toad that is believed by some to slow the spread of cancerous cells. The skin of the Bufo toad secretes a venom which is dried and dissolved in water. This solution, HuaChanSu, is injected into a cancerous area and targets specific cancer cells. HuaChanSu is undergoing further trials, and its effect is not completely understood.