On the other hand, in this study, the TT genotype in a subset of patients with G1 or G2 histologic malignancy of lung cancer (p = 0.0517) tends to occur more frequently, which is additionally confirmed by the result of the study for the mRNA expression of the ABCB1 gene, where it is demonstrated that the expression of mRNA is higher in the subgroup of patients with G1 or G2 (p = 0.0278). This evidence concerns the gene ABCB1 and lung cancer.