APOD and breast cancer: To explore whether the above genetic variation affected transcriptomic expression, we calculated the differences in gene expression value between BC and normal samples and observed that HLA-DRA, HLA-DPB1, and SPP1 were significantly increased in BC tissues, while, FABP4, PLIN1, and APOD were markedly downregulated in tumor tissues (Figure 3D, Supplementary Table S3).