Extended Data Figure 2. Eight B-ALL samples with signatures of UV exposure.

a, List of samples with UV signatures detected. b, Inference of ethnicity for cases CAAABF and PANXDR from 654 TARGET CGI samples by principle component analysis (Supplementary Note 10). c, Total spectrum of mutational signatures of the eight UV-mutation samples. d, SNVs of case CAAABF have a cross-validation rate of 90.4% with Illumina WGS data. e, High concordance of MAF values of SNVs derived from CGI and Illumina WGS, categorized by UV- and non-UV-mutations. Listed are Pearson’s correlation coefficient (r) and P value derived from linear regression. Numbers of SNVs are indicated in parenthesis. f, Inter-chromosomal distance and density plots for UV- and non-UV mutations in case CAAABF. Top panel: inter-mutational distance (log10 scale) of UV- (orange dots) and non-UV- (black dots) mutations. Chromosomal level gain and loss statuses are indicated. The results indicate uniform distribution of mutations with or without UV signature across the genome. Middle and bottom panel are density plots of UV- and non-UV-mutations, respectively, categorized by chromosomal loss (red) and diploid (blue) status in corresponding tumour sample. Estimated cluster centers are indicated by corresponding colors. The expected MAFs for clonal mutations at given purity and chromosomal ploidy status of corresponding tumour are listed in bottom panel. The density plots show that mutations with UV-signatures are clonal after adjusting for ploidy. g, Inter-chromosomal distance and density plots for the other seven cases (legend shown in f). h, ALL incidence by ethnicity obtained from the most recent registry (1973–2014) of Surveillance, Epidemiology, and End Results (SEER) Program Research Data (Supplementary Note 11). i, Mutation spectrum for all SNVs (All) and for UV SNVs (T-5) for each of eight cases. Total number of SNVs and Cosine similarity with COSMIC Signature-7 were indicated in each panel.