The purpose of this study is to collect blood and clinical data from patients with metastatic melanoma and renal cell cancer who have experienced spontaneous regression for studies of immune response and other factors that may influence these occurrences.

Spontaneous regression in patients with metastatic cancer is an incredibly rare event. It has been described after infection in cancer patients and also rarely in patients with renal cell cancer (usually after resection of the renal primary) and, less commonly, in patients with metastatic melanoma.

Primary Objective To collect peripheral blood from patients with metastatic melanoma and renal cell cancer and spontaneous regression for studies of immune response and other studies.

Secondary Objective To collect clinical data from subjects registered to this study. Clinical data collection will include demographics and cancer characteristics, history and treatment.

Inclusion Criteria

1. ≥ 18 years old at the time of informed consent
2. Ability to provide written informed consent and HIPAA authorization
3. Patients must have metastatic melanoma or renal cell cancer with spontaneous regression.
4. Willingness to undergo phlebotomy for research blood samples

Exclusion Criteria

1. Concurrent disease or condition that would make the patient inappropriate for study participation or any serious medical or psychiatric disorder that would interfere with the subject's safety
2. Dementia, altered mental status, or any psychiatric condition that would prohibit the understanding or rendering of informed consent

Patients with metastatic melanoma and renal cell cancer and spontaneous regression.