BRCA1 and breast cancer: We were thus able to obtain tissue-specific SuperSigs for mismatch repair deficiency, mutations in DNA polymerase delta or epsilon genes, mutations in the breast cancer susceptibility genes BRCA1 or BRCA2, methylation of the MGMT and IDH1 genes, and APOBEC (Figure 4b, Figure 4—figure supplements 31–67, Supplementary file 2, and Materials and methods).