Six genes (CXCL13, IL12RB2, CCL25, TNFRSF13C, TNFRSF8, and GDF5) were found in HPA database except IL21 and CCL7. The expression of CXCL13, IL12RB2, TNFRSF13C, TNFRSF8, and GDF5 in BC tissues were higher than normal tissues except CCL25 (Figure 7). This evidence concerns the gene IL21 and breast cancer.