Pinto et al. [73] studied epigenetic alterations in 56 familial BC patients (27 males and 29 females), showing that a higher methylation and lower expression of RASSF1A (a gene linked to the downregulation of ER-alpha) resulted, contradictorily, in an absence of ER expression in MBC, which did not happen in FBC. Here, ESR1 is linked to breast cancer.