GSTM1 and lung carcinoma: There was no statistically significant difference in the combination of both null and present genotypes of GSTM1 and GSTT1 between the two groups, which indicated no risk of lung cancer by both GSTM1 and GSTT1 null genotypes (OR = 1.41, 95%CI = 0.63–3.16, p = 0.421).