There were significantly lower frequencies of activating receptor NKp30+, NKp46+ and NKG2D+ NK cells in the tumour (n = 9–10) of OAC patients compared to the circulation (n = 19–20); NKp30: blood versus tumour (69.92% vs. 39.63%, p = 0.0051), NKp46: blood versus tumour (76.58% vs. 31.53, p < 0.001), NKG2D; blood versus tumour (75.02% vs. 54.21%) (Fig. 1b,c). This evidence concerns the gene KLRK1 and neoplasm.