No formalwear is required to attend the city’s most buzzed-about new fundraiser. Instead, the Cupid’s Undie Run, which benefits neurofibromatosis (NF) research through the Children’s Tumor Foundation, asks participants to strip off the usual gala garb—and then keep stripping down to their underwear. When the event debuts in Chicago on February 9, a horde of half-naked runners will expose themselves to the frigid February air as they run a 1.5-mile loop around Wrigley Stadium.

If it makes you uncomfortable, that’s the point. “Kids who have NF have to overcome big obstacles on a day-to-day basis,” says Tamara Forys, one of the event’s cocreators. “We wanted to put people in a situation [where] they’re doing something uncomfortable and a little bit crazy.” The race—or event, rather, as there’s no official winner or even a real finish line—ends at Houndstooth Saloon (3369 N. Clark St.), where the crowd of bodies and a little booze warms everyone back up as they celebrate their achievement (and put their clothes back on).

The idea for Cupid’s Undie Run began with Chad Leathers—whose brother Drew was diagnosed with Schwannomatosis (the most rare form of NF) when he was 11 years old—and Brendan Hanrahan and Bobby Gill. The genetic disease causes tumors to grow along the nerves all over the body, and its effects are highly variable. Some people live without knowing they have NF; others are plagued with learning disabilities, hearing loss, deformation of the bones, and other debilitating symptoms. In 2009 Drew became paraplegic and spent 183 days in the hospital; the rest of the year he was bedridden. Chad, who was living in Atlanta, moved to New York to be closer to Drew and work full-time for the Children’s Tumor Foundation. He was determined to help his brother, and to do so he had to bring more attention to the relatively unknown disease.

“We needed to stand out,” he says. “There are a thousand 5k’s a day, so how do we do something different? How about we take our pants off?” Chad and his friends thought it might just be crazy enough to work. “The idea was hatched mid-January 2010,” Chad says. “A month after that we had 650 undie-runners in six feet of snow running around the US Capitol.” In just four weeks, they raised roughly $10,000 for NF research. The event has grown exponentially since then; this year it expands into 11 new cities, Chicago among them.

Steve Lorberbaum, a DC-based lawyer and triathlete, was the event’s highest fundraiser last year. His 13-year-old daughter, Eliza, was diagnosed with NF1 when she was 18 months old and went through chemotherapy at the age of five. “[Fundraising] is different than the usual, ‘I’m running a triathlon; will you give me money?’” Lorberbaum says. “This is, ‘I’m going to be running in my underwear.’” Turns out, people will pay to see that: At press time, Lorberbaum was once again leading the pack nationally in dollars raised. Admittedly, “the weather in DC is not ridiculous,” he says. “I lived in Chicago for four years, so I know what ridiculous is like. But in reality,” he jokes, “the hour or so you spend in the bar before the run does make it seem less cold.”

And it’s making an impact. On December 6, 2012, after giving a speech at the CTF Gala, and with the assistance of his brother Chad, Drew lifted himself out of the wheelchair to which he had been confined for nearly four years. “Drew talks about [a time] when he was fearful not of the next day, but of the next minute,” Chad says. But thanks to the research efforts of the CTF, made possible by events like the Undie Run, “[Drew] is now looking into the future.” Chad continues, “The idea came from friends who are close to Drew, but our efforts [now include] the entire NF community, to end NF in all of its forms,” he says. “Passion is contagious.”

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