There were two errors in the article “Breast Cancer: Evaluating Tumor Estrogen Receptor Status with Molecular Imaging to Increase Response to Therapy and Patient Outcomes,” by Grabher (J Nucl Med Technol. 2020;48:191–201). The article incorrectly stated that 18F-fluoroestradiol was not an FDA-approved product. In fact, the product was approved before publication of the article, which was not corrected to reflect that change. There was also an error in the description of a Nottingham grade 3 tumor. A grade 3 tumor is considered poorly differentiated, as correctly stated in Table 3, not well-differentiated, as incorrectly stated in the text. The author regrets the errors.