Because McCormick Place is the largest convention center in the U.S., you can bet that it has a huge staff. Among the many workers here are a small group of people who spend their entire shift rubbing tennis balls on the floor. Part of the facilities team, these maintenance workers are responsible for removing shoe scuffs from the terrazzo floors in high-traffic areas. Using a tennis ball attached to a wood pole, they leverage the ball's felt cover with slight pressure to "erase" the scuffs. Low-tech? Sure. But imagine how different the place would look if this small team wasn't out there trying to keep pace with thousands of bustling conference attendees.It strikes me that they're a lot like the cancer researchers who are walking these halls. Cancer begins with damage to DNA, a scuff, if you will, on our cellular blueprint. Cancer researchers arrive at the scene and try to determine how to best erase the scuff or repair the damage. Like the workers here, they toil on and on in an attempt to keep pace with cancer's growth. Sometimes, they get lucky and discover a simple, low-tech means to erase the cancer (consider that radiation therapy has used essentially the same technology for more than 100 years).Could a cure for some cancers be simpler than we imagine? Is it an accident waiting to happen? I posed these questions to Michael K. Wong, MD, PhD, of the University of Southern California Norris Cancer Hospital. There might be a simple solution to some cancers, he said. The newest frontier in cancer research is immunotherapy: using vaccines to "teach" the immune system to recognize cancer cells, destroy them and "remember" them to prevent recurrence. It sounds complex but it's actually quite simple, he explained. The immune system is designed to respond this way. But cancer tricks it into thinking it's encountering a friend, so the natural response gets derailed.As for accidental discoveries, Mike quoted Louis Pasteur, the 19th-century French chemist and microbiologist. "Chance favors only the prepared mind," Pasteur said. Had he not been observant, curious and imaginative, Pasteur might not have been ready to respond to his circumstances and determine the next steps that led to life-changing discoveries.Whether cleaning scuffs at the nation's largest convention center or tackling cancer at the nation's largest research conference, one thing is clear: the race will not be won by the swift and the strong but by the dedicated and determined.