Role of TTV During First-line Immunotherapy Treatment in Patients With Renal Cell Carcinoma

This observational study is collecting blood samples to measure TTV (torque teno virus — a harmless virus used to measure immune strength) in patients with advanced kidney cancer (renal cell carcinoma) who are starting immunotherapy, to see whether TTV levels can predict how well patients will respond to treatment. **You may be eligible if...** - You are over 18 with a confirmed diagnosis of clear cell renal cell carcinoma (kidney cancer) - Your cancer has spread (advanced or metastatic) - You are about to start your first-line immunotherapy treatment (immune checkpoint inhibitor combinations) - You are able and willing to follow study procedures **You may NOT be eligible if...** - You have had prior cancer treatments (targeted therapy, immunotherapy, or radiation) - You have a prior cancer history - You have an active viral infection (such as HIV or hepatitis C) - You have received prior steroid treatment - You are unable to adhere to study procedures independently Talk to your doctor to see if this trial is right for you.