The researchers wanted to look at ER expression in atypical hyperplasia and see if there were any links to age at biopsy, the reason for biopsy, type of atypia, number of atypical foci, involution status, and family history, as well as see if there was any link between ER expression in atypia and subsequent breast cancer risk [221]. The gene discussed is ESR1; the disease is breast carcinoma.