In this study, using data generated from approximately 4000 tumor samples across 10 cancer types from TCGA, we performed integrative genomic and association analyses of the isoform expressions of APOBEC3A and APOBEC3B, APOBEC-mutational signature, germline APOBEC3A/B deletion, neoantigen loads and TILs. Here, APOBEC3B is linked to cancer.