ESR1 and breast cancer: Upstream regulator analysis on the differentially expressed genes revealed several activated mechanistic networks in breast cancer, including ERBB2 (Z score = 4.5), FOXM1 (Z score = 3.9), FOXA1 (Z score = 2.5), ESR1 (Z score = 2.4), and IGFBP2 (Z score = 2.2), while suppression of NURP1 (Z score = −6.1), TP53 (Z score = −3.4) was prominent (Supplementary File 3).