However, as other studies have reported conflicting results for CYP1A1 and GSTM1 polymorphisms in lung cancer [4,6], our study found neither significant risk of lung cancer for CYP1A1 variants or GSTM1 null genotypes nor possible combination effects of CYP1A1 and GSTM1 polymorphisms in the development of lung cancer. Here, GSTM1 is linked to lung cancer.