I didn’t know this before, but I found out that we all have a mesothelium. The mesothelium is the membrane that covers and protects most of the internal organs of the body. This is made up of two layers of cells: One layer which immediately surrounds the specific organ; the other one forms a sac around it. And then there’s Mesothelioma. Mesothelioma is a very rare type of cancer in which malignant or cancerous cells that are found in the mesothelium. A lot of the people who have developed mesothelioma have inhaled asbestos particles, most probably because of their jobs or the area they live in.