Cancer Evolution Is Associated with Pervasive Positive Selection on Globally Expressed Genes
Genes that are known to be associated with cancer (black) and all remaining genes (gray) were grouped based on the number of tissues in which their expression has been detected (out of 16 examined tissues). The frequency of genes within each bin is depicted. Cancer genes display a significant (P<0.0001, according to a χ2 test) enrichment for global expression patterns (defined as expression across all 16 examined tissues). At the same time, cancer associated genes are ∼2.5 times less likely than other genes to not be expressed in any tissue, or be expressed in a tissue specific manner (1–3 tissues, a significant depletion, P<0.0001).