For various subtypes of breast cancer, exosomal TF-Ag-α differentiated luminal A/B (n = 44) from normal controls (n = 29) with a sensitivity of 0.86, specificity of 0.97, and AUC of 0.96 (Fig. 6D and G), triple-negative (n = 9) from normal controls (n = 29) with a sensitivity of 0.89, specificity of 1.00, and AUC of 0.99 (Fig. 6E and G), and HER2-positive (n = 17) from normal controls (n = 29) with a sensitivity of 0.94, specificity of 0.97, and AUC of 0.99 (Fig. 6F and G). The gene discussed is ERBB2; the disease is breast carcinoma.