Certain findings on chest x-rays (see the section, “How Is Malignant Mesothelioma Diagnosed?”) that suggest asbestos exposure could prompt the need for further tests or close follow-up. However, the chest x-ray is not an effective test for early detection of mesothelioma in the general population. One test being studied is a blood test that measures the levels in the blood of osteopontin, a protein that is elevated in people who have lung damage due to asbestos. It is even higher if a person develops mesothelioma.