CD44 and neoplasm: Interestingly, CD24−/low/CD44+ cells exhibited induced HLA-E expression but reduced MICA/B expression in both cultured tumor cells (Figure 4A,B) and in tumor tissue from the in vivo xenograft model (Figure 7B,C), suggesting that the cytotoxic capacity of tumor-infiltrating NK cells may be strongly reduced by CSCs-rich RT-R-TNBC populations via alterations in signaling mediators for NK cells.