FOXC2 and nonpapillary renal cell carcinoma: In summary, our data suggest that FOXC2 and CLIP4 are associated with synchronous metastasis in ≤7-cm ccRCCs and could be used as potential biomarker genes from renal mass biopsy sample, which can determine the metastatic potential of these tumors could enable the application of personalized treatment strategies in ccRCC patients.