Samples from the TCGA breast cancer cohort were divided into high and low immune cell infiltration groups using a set of biomarkers, immune cell types, and immune-related pathways and functions. The overlap of differentially expressed genes from high and low immune cell infiltration groups, and primary and metastasis breast cancer patients downloaded from GEO was considered as candidate genes. After filtration of univariate cox analysis and co-linearity analysis, the final gene panel was identified.