In the transition of loose connective tissue, known as mesenchyme, into epithelial cells of the lung, DNA methylation can silence the tumor suppressor gene TCF21, leading to unregulated growth of a tumor.  Researchers at the University of North Carolina and the M. D. Anderson Cancer Center in Houston have found that hypermethylation of TCF21 is a valuable predictor of non-small-lung cancers developing.  That marker also could be quite useful in drug discovery.     MORE