Likewise, SMAD1 is negatively correlated with brain-specific relapse and expressed at slightly lower levels in basal-like tumors (Figure S6E-F), while Nuclear Receptor Binding Factor 2 (NRBF2) is positively correlated with brain-specific relapse and expressed at similar levels across breast cancer subtypes (Figure S6G-H). This evidence concerns the gene SMAD1 and breast carcinoma.