It's the stuff of fairy tales and folk medicine: using toad venom for cures.
But backed by a U.S. government grant, Dr. Lorenzo Cohen, director of the Integrative Medicine Program at the M.D. Anderson Cancer Center in Houston, has traveled 7,000 miles to Shanghai to test whether the traditional Chinese medicine can fight some of the deadliest cancers.
Watch the story on "World News Tonight" at 6:30 p.m. ET.
"I think it is very important that the world, as a whole, is starting to expand and look at indigenous medicines," Cohen said.
That's because Western medicine has not been effective against devastating diseases such as lung, liver and pancreatic cancer. In China, patients routinely receive a blend of Western and Chinese therapies, such as acupuncture.
Medicine that's extracted from toad skin may seem a little strange to Americans, but it has been accepted for centuries as a cancer treatment in China.
Until now, however, toad venom hasn't been put under the microscope of a Western clinical trial.
ABC News spoke with Shanghai trial participant Zhang Jingyi, who was going into his monthly CT scan. He has stage IV pancreatic cancer, painful and deadly. On average, fewer than 5 percent of patients live longer than five years beyond diagnosis.
"A few people at my factory died from this cancer," Zhang said. "I know what kind of disease this is."
His doctors prescribed toad venom to attack the tumor. They say they've seen it work before.
"There is research showing it induces apoptosis, which is spontaneous cell death, and there is research showing there is a decrease in the proliferation of cancer cells," Cohen said.
After four months of chemotherapy and toad venom, Zhang has reason to hope — his latest scan shows a significant, 15 percent reduction of his tumor.
"I am Chinese, so I trust Chinese medicine," Zhang said. But he credits both Chinese and Western wisdom for taking away his aching pain and fatigue.
It will take years to prove toad venom's effectiveness, but Cohen hopes someday ancient Chinese remedies will help patients back home, too.