We used GSE40447 to test our hypothesis, and the findings showed that IFIT5, XCL1, SPIB, BTLA, MS4A1, CD19, TCL1A, CD83, CD200, FCRLA, CD79A, and BIRC3 had great diagnostic value for whole blood of heart failure-related breast cancer patients and control sample (Fig. 7). This evidence concerns the gene BTLA and breast cancer.