ESR1 and breast cancer: Hub genes for this module, or genes with high connectivity, included FOXA1 and MLPH. FOXA1, a Forkhead family transcription factor, regulates ER binding and transcriptional activity.44FOXA1 expression correlates with luminal subtype A breast cancer and is a significant predictor of cancer-specific survival in ER+ tumors.45MLPH expression is also associated with longer survival in breast cancer.46 Further network visualization of genes within this ER-associated co-expression network revealed additional connections with AP1, AR (androgen receptor) and C/EBPα (CCAAT/enhancer binding protein).