Among the patients participating in trials focusing exclusively on hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer (HR+, HER2-) breast cancer, Caucasian predominance was even more remarkable, as these four trials featured a 97.4% White, 0.26% Asian, and 0.26% Black population among the 3454 patients. The gene discussed is ERBB2; the disease is breast cancer.