The COX-2 –1195G/A gene polymorphism is functional and associated with an increased risk for various human cancers; however, the results are controversial in lung cancer (Zhang et al., 2005; Dong et al., 2010; Coskunpinar et al., 2011; Tang et al., 2011; Moraes et al., 2017). Here, PTGS2 is linked to lung cancer.