Next, we determined if additional HR factors protect against APOBEC signature mutations like BRCA1/2 by using somatic base substitutions, copy number variations, and RNA-seq expression data from 309 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) tumors characterized by The Cancer Genome Atlas (TCGA). Here, BRCA1 is linked to endocervical adenocarcinoma.