Chen CH, Lu YS, Cheng AL, et al. - Researchers undertook a systemic evaluation of the prognostic impact of tumor-infiltrating immune cells in Asian patients with breast cancer. They used eight Gene Expression Omnibus data sets and The Cancer Genome Atlas data set to analyze gene expression profiles for Asian (n = 462) and Western patients (n = 2,186) with breast cancer in order to compare these populations for the immune score, composition, and prognostic influence of infiltrating immune cells. Both Asian and Western patients demonstrated that activated CD4 T cells and M2 macrophages were the most strongly related to survival. In this study, the variation in tumor immune microenvironments between Asian and Western patients was shown. Tumors of Asian patients showed higher Estimation of Stromal and Immune Cells in Malignant Tumours Using Expression Data immune score, which represents more plentiful tumor-infiltrating immune cells and explained in part their favorable prognosis.