rs17879961 (I157T), a likely causal[16] missense variant located in a CHEK2 functional domain that reduces or abolishes substrate binding[25], was previously reported to have opposite directions of effects on lung adenocarcinoma and lung squamous cell carcinoma and for lung cancer between smokers and non-smokers[26, 27]. Here, CHEK2 is linked to lung adenocarcinoma.