As we evaluated the clinical relevance of MCT-1, CXCL7, PD-L1 and IL-6 using the cDNA arrays of breast cancer and normal breast biopsies (OriGene TissueScan), we found that MCT-1, PD-L1 and IL-6 mRNAs were enriched in luminal, HER2(+) carcinomas and TNBCs, except for CXCL7, which was only induced in TNBCs (Figure 7A). This evidence concerns the gene PPBP and breast cancer.