AHRR and lung cancer: Our previous report that DNA methylation changes at cg05575921 in the AHRR gene and at cg03636183 in the F2RL3 gene were associated with lung cancer risk13 included mediation analyses which provided initial suggestive evidence that residual confounding was unlikely to explain the observed associations for cg05575921 and cg03636183, and that hypomethylation at these two sites may mediate the effect of tobacco on lung cancer risk.