ESR1 and breast cancer: Of various factors studies (i.e., genetic factors, metal exposure, clinical characteristics, lifestyles, pathogenic microorganisms and proteins), genetic factors have been a primary focus, with polymorphisms in genes such as PARP1, ESR1, FGFR2, FGF1, RBFOX2, FTO, IL-6, and HSPD1 identified as modifiers of BC risk and survival [20–23].