MYC and breast cancer: Potential interplay between mTOR blockade using AZD8055 and ER signalling was further investigated by PCR examination of the ER regulated gene pS2 as well as several ER-regulated genes more closely related to breast cancer cell growth: amphiregulin (important in TamR cells;[36], bcl2 (expressed in MCF7-X only), c-myc and cyclinD1.