Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding the nucleic acid binding protein 2, NABP2, also known as SSB1 (single-stranded DNA-binding protein 1) and OBFC2B (oligonucleotide/oligosaccharide-binding fold-containing protein 2B), when comparing primary tumors of the breast to the tissue of origin, the normal breast. SSB1 was also differentially expressed in the tumor cells of patients with triple negative breast cancer. SSB1 mRNA was present at significantly higher quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of SSB1 in primary tumors of the breast was correlated with recurrence-free survival in patients with basal subtype cancer. SSB1 may be of relevance to initiation, maintenance or progression of cancers of the female breast.