A drug made from blow fish poison is being tested to see if it can dull cancer pain.Early results show the drug, Tectin, is well tolerated and can relieve cancer pain for up to two weeks in some patients, says a study presented recently at a joint meeting of the American Pain Society and the Canadian Pain Society in Vancouver, British Columbia.The blow fish, also known as the puffer fish or Fugu, has long been a rather risky delicacy for dedicated sushi lovers. Only the most expert of sushi chefs prepare blow fish for customers, since consumption of the animal’s natural toxin can cause paralysis and even death.