- Patients may also be evaluated at the NIH Clinical Center by one or more of the following specialists: cancer doctor or blood specialist, medical geneticist, research nurses or clinical social worker. They may have blood and urine tests and a cheek swab or mouth wash to collect cheek cells. Some patients may also be asked to have x-rays and routine imaging, such as CT scans or ultrasound tests, cell surface markers, skin biopsy, and, with special consents, bone marrow biopsy, MRI or PET scans, apheresis or fluorescein angiography and photography.