Every February, thousands of undie runners in cities all across the U.S. come together, whether it be in-person or virtually, to support those affected by NF, a genetic disorder that causes tumors to grow on nerves throughout the body and affects 1 in every 3,000 births. Cupid’s Undie Run kicks off with drinking and dancing, then participants jog it out with a mile(ish) run and end it all with a dance party.