The premise of the study is that certain loci will be hypermethylated in the lung cancer specimen of the patients. For some loci (which we shall call Type I) the tumor will show significantly elevated methylation compared to adjacent histologically normal tissue, thus providing a cancer-specific methylation signal. Other loci (which we will refer to as Type II) may be methylated in the tumor as well as in the adjacent "histologically" normal tissue and/or WBCs. These loci will not be cancer-specific markers, though they may indicate precancerous changes or they may be indicative of "cancer risk". Their hypermethylation may be age-associated or environmentally induced, yielding "field effects" or "field defects". Field defects would consist of molecular alterations (in this case hypermethylation) that are not yet visible as histological changes.