1. Complete list of LC-MS myc interating protiens in the MCF7 cells, proteins highlighted in red are those differentially expressed from the LCC1 and LCC1 EGF treated cells. Supplemental Table S1 MCF7IdentifierUniprot Acc codeMrNo. of pepides Log (e) Band No. 4F2 cell-surface antigen heavy chain (4F2hc) ENSP00000367124P08195 71.11-2.3 1 78 kDa glucose-regulated protein precursor (GRP 78) ENSP00000324173 P11021 72.33-15.2 1 Actin-like protein (Fragment) ENSP00000306469Q562S9 42.01-1.7 1 actin-like protein Source: RefSeq_peptide NP_001017421 ENSP00000365045n/a 42.01-6.5 1 Alpha enulase ENSP00000234590P06733 47.11-3.3 1 Alpha-actinin 4 (F-actin cross linking protein) ENSP00000252699O43707 104.84-22.1 1 Annexin A2 (Annexin II) ENSP00000348640n/a 38.61-1.9 2 Antileukoproteinase 1 precursor (ALP) ENSP00000342082P03973 14.31-4.5 2 Apolipoprotein E precursor (Apo-E). ENSP00000252486P02649 36.1 1 -1.4 3 BA13B9.3 (NOVEL PROTEIN SIMILAR TO KRT8) ENSP00000334513n/a 55.12-7.4 1 Beta-catenin (PRO2286) ENSP00000344456P35222 85.4 1 -1.6 8 Clathrin heavy chain 1 ENSP00000269122Q00610 191.51-2.8 1 Cytokeratin type II. ENSP00000252245O95678 59.53-17.8 1 Desmoplakin ENSP00000369129 P15924 331.6 1 -1.3 6 Fatty acid synthase ENSP00000363777P49327 277.33-28.1 1 Filamin B (FLN-B) (Beta-filamin) ENSP00000349819O75369 230.72-11.9 1 Filamin-A (Alpha-filamin) (Filamin-1) ENSP00000353467P21333 279.81-5.3 1 Fructose-bisphospate aldolasea ENSP00000336927P04075 39.41-7.4 1 Glyceraldehyde 3-phosphate dehydrogenase, liver (GAPDH) ENSP00000229239P04406 36.03-24.1 1 Heat shock 70 kDa ENSP00000364805P34931 70.35-36.6 1 Heat shock 70 kDa protein 1 ENSP00000364802P08107 70.08-62.6 2 Heat shock cognate 71 kDa protein ENSP00000227378P11142 70.05-40.3 1 Heat shock protein HSP 90beta ENSP00000325875P08238 83.2 3 -22.7 6 Histone H2B.f (H2B/f) (H2B.1). ENSP00000350580 P3377813.91-7.7 4 Histone H4 ENSP00000352980P62805 11.41-3.3 4 Ig alpha-1 chain C region ENSP00000372520P01876 59.01-3.5 2 Junction plakoglobin (Desmoplakin III). ENSP00000311113P14923 16.51-5.7 2 K0256 Isoform 2ENSP00000261847 Q93073 116.5 1 -1.6 8 Keratinocyte proline-rich protein (hKPRP) ENSP00000357762Q5T749 64.1 1 -2.7 8 Lipin-3 (Lipin 3-like)ENSP00000362356 Q9BQK8 38.0 1 -1.2 8 L-lactate dehydrogenase B chain ENSP00000229319P07195 36.6 1 -4.9 6 Lysozyme C precursor ENSP00000261267P61626 16.51-5.7 2 Malate dehydrogenase, mitochondrial precursor ENSP00000327070P40926 35.52-10.0 1 Nuclear receptor corepressor 2 (N-CoR2) (SMRT) (SMRTe) ENSP00000348551Q9Y618 274.4 1 -2.6 7 Predicted: similar to 60S ribosomal protein ENSP00000349185n/a 29.61-4.0 2 Protein disulfide-isomerase A3 precursor ENSP00000300289 P30101 56.71-2.1 2 Puromycin-sensitive aminopeptidase(PSA) ENSP00000320324P55786 103.21-4.3 1 Pyruvate kinase, isozymes M1/M2 ENSP00000320171P14618 58.02-9.1 1 Receptor tyrosine-protein kinase erbB-4 precursor ENSP00000342235Q15303 146.71-1.1 1 Stress-70protein, mitochondrial precursor ENSP00000297185P38646 73.62-9.8 1 Transkeltolase ENSP00000296289B4E022 67.81-4.0 1 type I hair keratin KA35 ENSP00000347823Q6A163 55.6 1 -5.6 4 Ubiquitin-activating enzyme E1 ENSP00000366568P22314 117.81-1.3 1

2. Supplemental Table S2 Complete list of LC-MS myc interating protiens in the LCC1 cells, proteins highlighted in red are those differentially expressed from the LCC1 EGF and MCF7 cells

3. Supplemental Table S3 Complete list of LC-MS myc interating protiens in the LCC1 EGF treated cells, proteins highlighted in red are those differentially expressed from the LCC1 and MCF7 cells

4. Supplemental Table S4 Clinical trials examining the potential benefit of trastuzumab in Her2 low/Her2 negative breast cancer patients