While these are important areas of interest to breast cancer research and gains in RET expression have been reported in tumors or cell lines harboring ESR1 mutations [70, 71], and in cell line models of ESR1 fusions [72], relatively few studies have examined the specific influences of ESR1 alterations on the RET-ER signaling and transcriptional axis. The gene discussed is RET; the disease is breast carcinoma.