Mesothelioma is a rare form of cancer that typically forms in the lining of the lungs. In very rare cases, it forms in the lining of the heart, abdomen, or testicles. After several years of study, doctors discovered that mesothelioma is caused almost exclusively by exposure to asbestos. Once this process was better understood, the government began regulating the ways in which asbestos could be used. Before these regulations came into effect, many people were negligently exposed to the substance while on the job. Others, because it was often used in construction materials and manufactured goods. Those who were exposed to asbestos and later developed mesothelioma may have the right to sue those responsible. However, mesothelioma and how it relates to the law can be complicated, and those put in this position often have a lot of questions.