ESR1 and breast cancer: This difference may be due to the different sensitivity and specificity of the antibodies and probe used,19 or because of subjective interpretative variation in reporting, variable pre-analytical conditions, imperfect IHC methodology.18 ER and PR have important prognostic role in breast cancer and they also dictate the endocrine treatment, and important prognostic markers.14 Our study showed that in all of the patients, the positive rates of ER and PR were 54.8% and 61.6%, but results weren’t statistically significant (p>0.05).