To be more specific, the presence of CA9 SNP rs2071676 is correlated with a lower rate of advanced tumor stage in all types of EGFR, but became non-significant in lung adenocarcinoma patients with an EGFR mutation, implying the distribution of specific CA9 SNP and the phenotypes of EGFR may be similar if not identical. Here, EGFR is linked to lung adenocarcinoma.