The gene expression of 19 targets including GPER1, estrogen receptor alpha (ESR1), epidermal growth factor receptor (EGFR), MAPKs, Akt, and their downstream targets associated with estrogen signaling pathway in the main organs (hypothalamus, ovary, uterus, liver, kidney) of nude mice with SK-BR-3 xenograft tumor were analyzed by RT-qPCR technology. The gene discussed is GPER1; the disease is neoplasm.