These tumours also display a higher extent of copy number aberrations (mean fraction genome altered: 19% versus 12%), and more frequent mutations in genes such as BAP1 (12.3% versus 5.4%), SETD2 (12.7% versus 8.1%) and MTOR (6% versus 4.7%), which are associated with more aggressive disease (though only BAP1 has a statistically significant difference—P value 0.025, Fisher's exact test). This evidence concerns the gene MTOR and neoplasm.