Leaders in the stem cell industry have converged on Madison for a couple of days. The city is hosting a worldwide summit on stem cell research. Scientists believe it could someday provide cures for diseases such as Parkinsonâ??s or cancer. While the industry has changed, Wisconsin has remained at the forefront of the research. The industry has changed somewhat, but Wisconsin has remained at the forefront, and thatâ??s why itâ??s ground zero this week. WUWMâ??s Marti Mikkelson reports.