TOP2A rs471692 and DUSP6 rs2279574 SNPs were in complete linkage disequilibrium; however, frequency of DUSP6rs2279574 genotype was significantly different between the case and control, that is, DUSP6rs2279574a/A and A/C genotypes might contribute to an increased risk of lung squamous carcinoma compared with the C/C genotype.
These results indicate that DUSP6 acts as a negative feedback regulator of ERK in adenocarcinoma progression, but that DUSP6 does not play a role in the downregulation of ERK in squamous cell carcinoma.