To examine whether germline variants were able to predict tumor recurrence, we used whole-exome sequencing data (i.e., from the National Cancer Institute (NCI) Genomic Data Commons (GDC)) of healthy tissues from 755 estrogen receptor-positive (ER+) breast patients by applying our recently developed method, eTumorMetastasis.10 ER+ subtype represents ~70% of breast cancer patients, thus, in this study, we used only patient data from this subtype. Here, ESR1 is linked to breast cancer.