The estrogen receptor-related factor (ERRF) is a recently identified protein whose expression is upregulated in multiple cell lines and primary breast cancer tumors. Increased ERRF expression was significantly associated with ER or progesterone receptor (PR) positivity even in HER2-negative tumors. This higher ERRF expression correlated with better disease-free survival and overall survival. In two ER-positive breast cancer cell lines, knockdown of ERRF suppressed cell growth in vitro and tumorigenesis in xenograft models, suggesting that ERRF plays a role in estrogen-ER-mediated breast cancer cell growth and may thus be a potential therapeutic target.
C1orf64; ER-related factor; ERRF; Estrogen receptor-related factor; RP11-5P18.4; Steroid receptor-associated and regulated protein; Steroid receptor-regulated protein; uncharacterized protein C1orf64 homolog