ESR1 and breast cancer: The selected 13 nodes contribute to different breast cancer-related pathways: cell cycle (CYCLIN D and P21), apoptosis (BCL2, BID, CASP3, and FADD), estrogen signaling (ESR1), EGFR signaling (PAK1), progesterone signaling (PGR), Wnt signaling (WNT1), JAK/STAT signaling (GATA3 and STAT3), and PI3K/AKT signaling (MTORC1) pathways.