Evaluation of Anti-PD-1 Therapy by Monitoring T Cell Responses in Melanoma, Lung and Other Cancer Types

This study is monitoring how the immune system — specifically T cells — responds to immunotherapy drugs called anti-PD-1 or anti-PD-L1 treatments in people with various cancers. The goal is to find better ways to predict and measure whether these treatments are working. **You may be eligible if...** - You are 18 years old or older - You have locally or regionally advanced, or Stage IV cancer confirmed by tissue biopsy - Your doctor has recommended starting treatment with an anti-PD-1 or anti-PD-L1 immunotherapy drug **You may NOT be eligible if...** - You have early-stage cancer not receiving immunotherapy - You are not eligible for anti-PD-1/PD-L1 treatment Talk to your doctor to see if this trial is right for you.