CCNA2 and breast cancer: As shown in Table 1, four (CCNA2, CENPN, DEPDC1, and TTK; DOE-A) and three genes (ABAT, LRIG1, and PGR; DUE-A) were identified as differentially over- and under-expressed genes, respectively, as described in “Methods” and they were selected as novel biomarker candidate genes for breast cancer and were subjected to the subsequent analyses.