(Pittsburgh) -- More than 3,000 representatives from cities across the country are gathering in Pittsburgh through Saturday for the National League of Cities summit.

The Washington, D.C.-based advocacy group meets in a different city each year.

The group advocates for laws and policies that affect cities, and is in Pittsburgh to learn about the city's ongoing post-industrial transformation into a medical research and high-tech hub.

Clarence Anthony, the group's CEO, says "Pittsburgh has done so many things in its transformation, so leaders can come here and they can learn.''

Although the group is gathering at the David L. Lawrence Convention Center downtown, they'll also go into some of the city's 88 neighborhoods for mobile workshops, as well as visits to the city's Cultural District and learn about efforts to redevelop city riverfronts.