ERBB2 and breast carcinoma: Finally, Zavala et al., in 2022, analyzed hormone receptor (HR) and HER2 expression in 1943 breast cancer patients, finding the following: HR positive with HER2 negative (52.4%), HR positive with HER2 positive (18.7%), HR negative with HER2 positive (12.9%), and HR negative with HER2 negative (16.0%) .10