There are a lot of reasons for lung nodules, some of them we don't know what causes them, some of them are from histoplasmosis which is a fungus that's pretty common in Frederick County - those nodules are benign. Of course some of them are lung cancer, so there's lots of various reasons. It could be from... you may not necessarily get a nodule on your screening but you may have some scarring from smoking. That doesn't necessarily mean you have lung cancer, it just means you have scarring or that you've had a lot of pneumonias, those types of things.