Furthermore, we found that 15 mRNAs (HLA‐DRA, OAS2, ABRACL, COX6C, GAPT, SHMT2, RAB3D, SPI1, KIAA0040, RNF4, CDC42SE1, ORAI2, DENN2D, LMNB1, and HMGA1) were also highly expressed in BC tissues based on the TCGA database (Figure 6B‐D), which could be the potential circulating diagnostic biomarkers for BC. This evidence concerns the gene SHMT2 and breast cancer.