In particular, by checking the expression data of 1104 cancer and 113 normal samples from the TCGA project in ENCORI database, we found that these four genes showed strong expression in the breast cancer specimens as compared to their expression in normal breast tissue ( Including : MAD2L1, Fold change: 4.28, Adjusted P value: 1.4e−70; CCNA2, Fold change: 6.88, Adjusted P value: 3.2e−91; CCNB1, Fold change: 5.63, Adjusted P value: 1.8e−111; CDK1, Fold change: 8.54, Adjusted P value: 5.3e−121). The gene discussed is CCNA2; the disease is cancer.