Protein in deadly spider venom blocks "death signal" after heart attack The venom of Australian funnel web spiders could have life-saving potential As unlikely as it may seem, the venom of the deadly funnel web spider could prove a valuable source of a number of life-saving medicines, including drugs that kill skin cancer and reduce brain damage in stroke victims. Adding to these possibilities is new research demonstrating how a drug candidate built off a molecule in this spider venom can stop the "death signal" that results from a heart attack, potentially providing first responders with a powerful new way to intervene.