ESR1 and breast cancer: We observed no significant association between germline APOBEC3B deletion with any clinicopathologic features of breast cancers such as age of diagnosis, tumour grade, tumour size, lymph node involvement, estrogen receptor (ER) status, progesterone receptor (PR) status, human epithelial receptor 2 (HER2) status, and triple-negative breast cancer (TNBC) status in the overall cohort as well as in the Chinese and Indians (Table 3, Additional file 1: Table S5).