This episode of The Motley Fool's Market Checkup is dedicated to the world's largest pure-play biotech stock, Gilead Sciences (NASDAQ:GILD)Market Checkup gives a full examination of Gilead's second-quarter results, takes a closer look at the company's current product portfolio, and analyzes the future drugs that have investors excited about the stock's future.

In this video, health-care analysts David Williamson and Max Macaluso drill down on Gilead's strong drug development pipeline. Watch and find out what makes pending hepatitis-C drug candidate sofosbuvir both so exciting and potentially dangerous for Gilead investors.

Sofosbuvir is a nucleotide inhibitor, and the only member of its hep-C drug class to make it through clinical trials without major safety issues. However, if a problem reared its head once the drug were on sale, it could have a devastating effect on Gilead shares. Watch David and Max discuss this "what-if" scenario in the video.

David Williamson has no position in any stocks mentioned. Follow David on Twitter: @MotleyDavidMax Macaluso, Ph.D. owns shares of Gilead Sciences.

The Motley Fool recommends Gilead Sciences and Vertex Pharmaceuticals. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.