CXCL12 and lung cancer: Interestingly, genes associated with the hypermethylated CpGs in the 56Fe affected group showed a significant overlap with genes whose promoters were previously shown to undergo DNA hypermethylation in lung cancer cells43 (n = 31, FDR corrected p = 3.75 e-12; Fishers Exact), including several homeobox containing transcription factors, the RNA binding protein lin28A, and the chemokine, CXCL12 (Supplemental Table 2).