Because the design includes diverse study domains, diverse questions can be addressed that are inaccessible to more constricted designs. For example, depression (a behavior) is known to be related to smoking (an exposure). However, only an integrated design can establish whether it is also related to lung cancer risk (taking into account smoking), or lung cancer survival (taking into account other prognostic factors), or whether genes related to smoking or depression are the same ones that influence lung cancer risk [22]. Through the parallel use of high technology approaches applied to tissue samples, similar questions can be addressed on the molecular level. For example, we may assess a gene through a chromosomal region, polymorphic variant, expression or methylation pattern, or its protein product. Eventually all these approaches can be combined to assess cancer networks; 3) The integrated approach can identify genes or other factors that span multiple stages in the development of disease to its denouement. In general, the major question of whether the same genes that contribute to the 'cause' of a cancer also stimulate its progression has been generally sidestepped by traditional epidemiological study designs. 4) It provides a study crucible where scientists of diverse disciplines can work
