Figure 4. Cancer-associated mutation spectra in driver genes and structural variation in normal ASCs.

a, Spectrum of point mutations in cancer driver genes APC, TP53, SMAD4 and CTNNB1 identified in colorectal and liver cancer. The total number of somatic point mutations per gene per cancer type is indicated. b, Read-depth analysis indicating a relatively small deletion (~90 kb) located within a common fragile site (FRA2I) in intestinal ASC 11-a. Each point represents the log₂ value of the GC-corrected read-depth ratio per 5-kb window. Dashed lines indicate breakpoint regions; a schematic representation of the identified structural variant with associated genomic and breakpoint features is depicted below. c, Two large (>1 Mb) tandem duplications identified in liver ASC 14-a with microhomology at the breakpoints; duplications are indicated in the schematic representation of the identified structural variants below the graph. d, A complex structural variation (an unbalanced translocation involving 3 chromosomes) identified in colon ASCs 4-b and 4-e. Coloured lines in the schematic below show the predicted derivative chromosomes. e, Read-depth analysis indicating a trisomy of chromosome 13 in colon ASC 3-c. Each data point represents the median chromosome copy number per 500-kb bin plotted over the genome, with alternating colours for each successive chromosome.