Additional Study Information: This study is an exploratory biopsy sample study. Its purpose is to better understand why your metastatic cancer has progressed and stopped responding to checkpoint inhibitors. The information gained from this study may be valuable for understanding the mechanisms that cause resistance to immunotherapy. Cancers include: bladder cancer, brain and spinal tumors, breast cancer, colon and rectal cancer, esophageal cancer, gynecologic cancers (cervical cancer, ovarian cancer, uterine (endometrial cancer), kidney cancer/adrenal cancer, liver cancer, lung cancer, skin cancers, melanoma, pancreatic cancer, prostate cancer, sarcomas, stomach cancer, testicular cancer, and thyroid cancer.