MTOR and cancer: Using phylostratigraphy, Cisneroset al. 81 found that recessive cancer genes older than 900 million years are homologs of the ancient genes in bacteria that turn up mutation rates when the cells are stressed–suggesting that the well-known genomic instability of cancer can be interpreted as a reversion to an ancient prokaryotic stress response, a phenomenon recently confirmed by the analysis of Cipponiet al.82 showing mTOR (mammalian target of rapamycin) signaling orchestrates stress-induced mutagenesis, facilitating adaptive evolution in cancer.