COL6A1 and nonpapillary renal cell carcinoma: Results: In multivariate analysis of TCGA cohorts, COL6A1 high expression was predictive of poor prognosis in ccRCC patients’ overall survival (OS) (HR: 2.588 95%CI 1.616–4.146) and disease free survival(DFS) (HR: 3.106 95%CI 1.534–6.288).