BOSTON (AP) — Hundreds of people are planning to walk around the Boston Common to raise money for a cure for lupus.

Organizers say they're trying to reach a goal of $130,000 in donations to fight the autoimmune disease. Millions of Americans suffer from lupus, but researchers are still trying to figure out what causes it and how to treat and eventually eradicate it.

Participants will walk a mile around the Common on Saturday morning.

For the second year in a row, downtown Boston's Zakim Bridge will be lit purple to show support for those walking.

Sponsors include Biogen, EMD Serono and Brigham and Women's Hospital's Lupus Center.