Systematic identification of the cancer pathways and molecules related with breast cancer immunogenicity.

To identify molecular features related to immunogenic activity in breast cancer (BC) and provide new targets and directions for BC immunotherapy, we firstly used ESTIMATE to evaluate the degree of immune cell infiltration of the BC patients in TCGA and METABRIC, and explore the relationship between the degree of immune cell infiltration and prognosis of BC patients. Then, we identified the cancer pathways, proteins and miRNAs related to BC immunogenicity, predicted the target genes of these miRNAs, and identified the pathways related to these target genes with KEGG pathway enrichment analysis. We also explored the correlation between PD-L1 expression level and cancer pathways and found that PD-L1 expression showed a positive association with cancer-related pathways. In this article we have successfully identified several cancer-related pathways, proteins, miRNAs, and their target genes, which provided promising new targets for BC immunotherapy. And PD-L1 blockade therapy may be more effective in BC patients with the activation of some cancer-related pathways.