One of these proteins binds the scaffold protein MNAR and is co-activated by each of the three p160 proteins, such as SRC-1. Mutations in one of these proteins between residues 536 and 538 in helix 12 disrupt its binding domain and are particularly oncogenic. The presence of one of these proteins (-5[1])differentiates the cell line MCF7 from MCF10A. A G525R mutant of one of these proteins, which is sensitive to the metabolite 4-OHT, is commonly used to study (*) embryonic-lethal genes since their expression can be controlled by administration of tamoxifen, which targets these proteins. The nuclear and membrane (10[2])variants (10[1])of these proteins each bind all four isoforms of their primary ligand, which are distinguished by their one to four hydroxyl groups. For 10 points, name these proteins that with HER2 and the progesterone (10[1]-5[1])receptor (10[1])are commonly (10[1])used to (10[1])delineate breast cancer severity. ■END■ (10[3]0[5])