Peter Thiel backed this startup that wants to cure cancer, and it's worth $5 billion

Stemcentrx, a startup with funding from billionaire tech investor Peter Thiel, just came out of stealth at a $5 billion valuation, the Wall Street Journal reports.

Last month Stemcentrx raised a $250 million round at a $5 billion valuation, according to the Journal.

Stemcentrx was "largely unknown outside biotechnology circles" prior to emerging from stealth operation, according to the Journal.

The startup wants to cure cancer by killing cancer stem cells - the cells that spread cancer through the human body and resist cancer treatments.

The startup has five drugs in clinical trials, according to the Journal. If the company is successful, patients who take Stemcentrx drugs and also undergo chemotherapy treatments could stand to improve their odds of beating cancer.

Peter Thiel's Founders Fund and Artis Ventures are among Stemcentrx's investors. And Founders Fund's investment in Stemcentrx is the biggest the VC firm has ever made, the Journal reports.

Peter Thiel's "fight against death" has been well-documented. His Breakout Labs funds "radical science" and "bold ideas," including ways to cool organs to preserve them and projects that grow bones from stem cells.

Thiel thinks that the "great enemy" of humanity is death. "I believe that evolution is a true account of nature," he told the Washington Post. "But I think we should try to escape it or transcend it in our society."