Inclusion Criteria:  Patient followed for metastatic clear cell renal cell carcinoma. Age ≥18 years old. Performance Status (PS) according to Eastern Cooperative Oncology Group (ECOG) = 0, 1 or 2 Patient treated with a VEGF-R inhibitor: pazopanib or cabozantinib, in the 1st, 2nd or 3rd line of treatment for metastatic kidney cancer. If patient doesn't have renal failure -> group 1, or if patient has chronic renal failure according to the moderate stage Chronic Kidney Disease - Epidemiology (CKD-EPI) formula (Clr <60 ml / min, stage 3) -> group 2, or if patient have chronic renal failure according to the CKD-EPI formula of severe or terminal stage (Clr <30 ml / min, stage 4 and stage 5), with or without dialysis -> group 3. Willingness and ability to comply with scheduled visits, treatment plan, laboratory tests and other study procedures. Patient having given informed, written and express consent. Affiliation to the French Social Security System.  Exclusion Criteria:  Indication other than clear cell renal cell carcinoma for these same ITKs Pregnant or breast-feeding subjects Patient whose regular follow-up is impossible for psychological, family, social or geographic reasons, Patient under guardianship, curatorship or safeguard of justice Participation in another clinical study with a research product during the last 30 days before inclusion.