In our study, based on the in silico analysis, OS-associated promoter CpG sites signature was constructed for prognostic prediction of BC, of which four dmCpG sites were identified, including cg00822495 (OTX2), cg03225817 (GRIA4), cg06884401 (FAM13A), and cg09869811 (NUTF2). Here, FAM13A is linked to breast cancer.