ERBB2 and breast cancer: In total, when CTC-negative and -positive cases were considered, EMT-related CTCs occurred more frequently in the luminal B/Her2+ (LumB/Her2+) BC subtype (20.4% of cases), whereas epithelial CTCs occurred in triple-negative breast cancer (TNBC) (22.4% of cases) (Chi2 test, p = 0.047, Tables S3 and S4).