ESR1 and breast cancer: Consistently, Bae and colleagues [46] indicated that ER + /PgR− and ER−/PgR + breast cancer were in associations with poorer DFS and OS than ER + /PgR + tumors and findings of Rakha et al. [47] adopting 1,944 breast cancer patients suggested that the single-positive patterns, including ER + /PgR− and ER−/PgR + , breast cancer exhibited an increasingly aggressive clinicopathological features than ER + /PgR + subtypes and an opposite profile in comparisons with the ER−/PgR− subtype.