Similarly, when compared to all other tumors (basal-like, HER2-enriched, luminal A, luminal B and normal breast-like) as a single group, the claudin-low tumor subtype maintained its characteristic for low to absent expression of E-cadherin and claudin 3 (45% vs. 15% for E-cadherin, P < 0.005; 59% vs. 22% for claudin 3, P < 0.001; χ2 test) (Figure S3 in Additional file 1). The gene discussed is ERBB2; the disease is neoplasm.