KLRD1 and cancer: Since both the monospecific mAbs such as TFL-033 and inhibitory receptors NKG2A/CD94 on NK and cytotoxic T cells bind to the same sequence of the peptides located in the HLA-E α1 and α2 helices, these HLA-E-specific mAbs may have the potential to block the inhibitory pathway responsible for the poor outcome of the NK and CD8+ T cell-based cytotoxic killing of cancer cells in some cases.