Extended Data Fig. 8: Enrichment of colibactin mutagenesis as an early clonal event in early-onset and late-onset colorectal cancers.

a, Box plots indicating the fold-change of the relative contribution per sample of each signature between clonal and subclonal single base substitutions (SBS, left) and small insertions and deletions (ID, right). Signatures that generated clonal somatic mutations in fewer than 10 samples and also generated subclonal somatic mutations in fewer than 10 samples were excluded from the analysis. The line within the box indicates the median, while the upper and lower ends indicate the 25^th and 75^th percentiles. Whiskers show 1.5 × interquartile range, and values outside are shown as individual data points. b, Boxplots indicating the fold-change of the relative contribution per sample of each signature between early clonal and late clonal SBS (left) and ID (right) with samples separated by age of diagnosis in early-onset (under 50 years of age; purple) and late-onset (50 or over; green). As in Fig. 4a, SBS signatures that generated early clonal SBSs in fewer than 50 samples and late clonal SBSs in fewer than 50 samples, as well as ID signatures generating early clonal IDs in fewer than 20 samples and late clonal IDs in fewer than 20 samples, were excluded from the analysis.