CA9 and metastatic malignant neoplasm in the lymph nodes: For the male population, the significantly lower tumor stage and lower risk for developing lymph node metastasis still presented in those with EGFR wild type and CA9 SNP rs2071676, and the tumor stage in all forms of EGFR with CA9 SNP rs2071676 showed non-significant results compared to those with wild type CA9.