ESR1 and neoplasm: Among the patients, 73 (14%), 174 (32%), and 68 (15%) had discordant ER, PR, and HER2 statuses in their primary tumor and metastasis, respectively, indicating statistically significant discordance between ER and PR status, but not HER2 status (p < 0.001, p < 0.001, and p = 0.225, Tables S2–4).