We are doing this study learn more about circulating immune cells and circulating tumor cells (CTCs) in patients with metastatic renal cell carcinoma or metastatic urothelial carcinoma.

We are also looking at the bacteria in your gut and urinary tract to learn about how these bacteria affect how your cancer responds to immunotherapy.

Advanced Kidney and Bladder Cancer

Adult patients with renal or bladder cancer who are planning to start an immunotherapy.

If you choose to join this study, there will be four different timepoints.

At these timepoints, we will:

• Collect blood, urine and stool samples
• Review your chart to find out how your body is reacting to the immunotherapy and how your cancer is responding to the immunotherapy