It may well be that there are other important genes lost or altered in these cancers, which have not yet been discovered. Cancer Basics Meningiomas are benign tumours of the brain and spine. Since benign tumours do not invade the surrounding tissues or spread, most of them are harmless. However, because meningiomas grow in the brain or the spine, they can still cause severe problems. Recent studies have suggested that these tumours are more common than we previously thought.
Genes are the coded instructions for all the functions of cells.
One of the main causes of cancer is defects in the genes which contain the instructions for cell growth and division. Inside every cell, the genes are carried on long, thin structures called chromosomes. Human cells have 23 different chromosomes.