HLA-E and breast cancer: Recent results have shown that IFN-γ induced by BCG treatment enhances HLA-E and PD-L1 expression in recurrent tumors and NKG2A expression in intra-tumoral NK and CD8T cells and have provided a framework for a combined NKG2A and PD-L1 blockade strategy for the bladder-sparing treatment of BCG-unresponsive BC [12].