KLRK1 and malignant glioma: Using a technology to silence TGF-β1 and -β2 genes in malignant glioma cells, Friese et al. revealed that these tumor cells did not down-modulate the NKG2D expression on NKL cells (a NK cell line); moreover, strong surface MICA expression on tumor cells was also observed when they blocked the TGF-β production promoting a strong recognition by immune cells [52]; these results support the key role of TGF-β in the MICA/NKG2D pathway.