MACROD1 and breast cancer: In particular, in case of hormonally responsive BC, it has been shown that CK18 has a regulatory role as it can effectively associate with and sequester the estrogen receptor-alpha (ER-α) target gene and ERα coactivator LRP16 in the cytoplasm, thus attenuating ERα-mediated signaling and estrogen-stimulated cell cycle progression in BC cells [31].