GPX3 and nonpapillary renal cell carcinoma: First, as a tumor suppressor gene related to higher nuclear grade, GPX3 suppression may have a negative influence on patients’ clinical outcome, and detection of GPX3 methylation may provide prognostic information on ccRCC, especially when TSG hypermethylation can be detected in patients’ serum and urine samples, just like RASSF1A, tissue inhibitor of metalloproteinase-3 and CDH1 methylation [28].