Because A3B expression is markedly upregulated and variations in its expression contribute to the different median mutation loads observed between multiple cancers (Supplementary Fig. S3)8, we next examined whether this correlation is also valid when MYBL2 is substituted for A3B. To test this, we analyzed transcriptomic and exomic data from TCGA dataset stratified cancer types. This evidence concerns the gene APOBEC3B and cancer.