ESR1 and cancer: A multivariate Cox analysis was then performed including the remaining 12 pathways—PI3K–Akt signaling pathway, Ras signaling pathway, EGFR tyrosine kinase inhibitor resistance, ErbB signaling pathway, FoxO signaling pathway, HIF-1 signaling pathway, VEGF signaling pathway, B cell receptor signaling pathway, PD-L1 expression and PD-1 checkpoint pathway in cancer, Choline metabolism in cancer, Estrogen signaling pathway, and Notch signaling pathway—along with BED, estrogen receptor status, and Ki-67 index as clinical covariates.