B2M and metastatic malignant neoplasm in the lymph nodes: In a separate study conducted with a small set of tissues (n=14), we observed that B2M maintained its high prognostic accuracy for lymph node metastases (AUC=0.79) when more classical reference control genes TBP (Ohl et al, 2006) or UBP (Andersen et al, 2004) were substituted for Spint2 (not shown).