Mutations in gene protecting body leads to development of cancer

Note: the PTEN mutation has and is being widely studied in ovarian cancer

"The study examined mutations in a gene called PTEN. People who inherit a mutated copy of this gene have Cowden syndrome, a condition that carries a high risk of cancer in a number of organs, including the breast, thyroid and ovary. In addition, PTEN is frequently mutated in normal body cells leading to prostate, lung and pancreatic cancers."