199

---

Click the image below to view the full size version of this cover.

Issue 199: Do tumor cells sometimes make the same mistake twice? In our Nature Genetics paper, we identify biallelic mutations, where the same base is mutated independently on both parental alleles, across 2,658 cancer genomes and highlight the processes behind them. These mutations violate the infinite sites model of molecular evolution, a cornerstone of tumor phylogenetic analysis which is also often implied when calling, phasing and interpreting variants or studying the mutational landscape as a whole. The cover shows copy number estimates for chromosomes and mutations across part of a melanoma whole genome. Biallelic parallel mutations (blue circles) can be identified when their copy number is equal to the total copy number (red bars) in heterozygous regions of the tumor genome.