PGR and breast neoplasm: Although the distinct microbial characteristics of breast tumor tissues have been compared with those of normal adjacent tissue, breast skin tissue, breast skin swabs, and buccal swabs [14], the association of the microbial community with gene expression has not been reported, and few analysis based on the ER, progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status has been described.