A new mesothelioma test, approved in December 2008, faced use over 2,000 times in the Philadelphia, Pennsylvania lab of Rosetta Genomics. At its approval, the miRview meso test began to be distributed to the public in both Israel and Turkey and on a commercial basis throughout the United States. The miRview meso test has the ability to distinguish malignant pleural mesothelioma from other types of cancer that occur in the lungs. Proper diagnosis of mesothelioma can help physicians to more specifically hone treatment. Pleural mesothelioma is a cancer of the tissues lining the lungs. The only known cause is from the inhalation of asbestos fibers. Asbestos was a common construction material used for most of the 20th century in the Western Hemisphere, but its use was regulated in nations such as the United States, Australia, and Great Britain when its carcinogenic properties became known in the late 1970s and early 1980s. Despite these regulations, incidences of mesothelioma still occur since the disease has a latency period of 30 to 40 years. Those exposed to asbestos in the middle of the 20th century through their work find that they are being diagnosed with mesothelioma and other lung cancers decades after they have retired. The test is able to assess the amount of microRNAs that are from mesothelioma cells and non-mesothelioma cells. MicroRNA is a recently uncovered category of genes that are specific to certain tissues and tumors. A sample from the tumor is taken, and a measurement of the amount of microRNA from both mesothelioma and other cells is taken. These are scores that can determine if the cancer being looked at is mesothelioma. Only a physician can send a sample of the patient’s tumor to the Rosetta Genomics’ lab. The lab then returns the test results within 10 business days. This test is the only means physicians have to determine if a patient is suffering from malignant mesothelioma or a metastasizing tumor. The miRview meso test has shown to be 100 percent accurate in high confidence cases of cancer. This breakthrough will mean those with mesothelioma will be more likely to get the treatment they need.