A 43-year-old female with stage IIIA (cT3N1M0) ER- and PR-positive, HER2-negative invasive ductal carcinoma of the right breast presented to the emergency department with a 2-week history of fatigue, myalgias, nonproductive cough, and shortness of breath. The gene discussed is ERBB2; the disease is invasive ductal breast carcinoma.