The AUCs of the tumor model in the subset of luminal A, luminal B, HER2 enriched, and triple-negative breast cancer were 0.728 (95% CI, 0.556–0.899), 0.812 (95% CI, 0.734–0.890), 0.976 (95% CI, 0.910–1.0), and 0.741 (95% CI, 0.489–0.993), respectively. The gene discussed is ERBB2; the disease is neoplasm.