PROM1 and breast cancer: Utilizing the scores pre-calculated by Thorsson et al. [41], we found that CD133-high ER+/HER2− BC was associated with greater lymphocyte infiltration, TGF-β response (both p < 0.001), and T cell Receptor (TCR) richness (p = 0.038), suggesting a proinflammatory microenvironment in the TCGA cohort (Fig. 5A).