This type of cancer forms in blood cells called plasma cells. These are special white blood cells that help
your immune system. They mainly stay inside your bone marrow, a soft, spongy tissue found in your large bones. Your bone marrow is
where new blood cells are made. If you have multiple myeloma, your marrow becomes crowded with cancerous plasma cells. They crowd
out healthy blood cells. They produce abnormal proteins that cause problems in your body.