ESR1 and breast carcinoma: As stated before, estrogen receptor antagonists exert toxic effects on various microorganisms related to breast cancer (Porphyromonas gingivaliis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus mutants, Bacillus stearothemphilus, and Enterococcus faecium) [47,49].