ESR1 and breast carcinoma: By retrospectively analyzing the clinicopathological data on breast cancer collected from representative hospitals of 7 traditional areas in China in one random month from each year between year 1999 and 2008, we found that: 1) The rate of the use of hormone receptor (HR) testing was 83.8% (3529/4211), with the estrogen receptor-positive (ER+) rate and/or the progesterone receptor-positive (PR+) rate being 67.9% (2395/3529), and the ER-PR rate being 32.1% (1134/3529).