POLQ and cancer: We analyzed enrichment of any of the 82 COSMIC signatures (65 SBS signatures or 17 ID signatures) according to POLQ mRNA expression level and POLQ mutation status in BRCA-mutated cancers (Supplementary Figure S1). POLQ expression was analyzed using RNA-seq data; the top and bottom 33% were considered as POLQ high-expression group and low-expression group, respectively.