In addition, several groups have independently shown the induction of stress ligands of NKG2D (including the MICA/B and ULBP ligands) on the surface of various tumor cell types and the corresponding engagement by immune cells expressing the activator receptor NKG2D, such as NK cells and γδT-lymphocytes ultimately results in the elimination of tumor cells expressing those stress ligands (Hu et al., 2012; Luis Espinoza et al., 2013; Pan et al., 2017). This evidence concerns the gene KLRK1 and neoplasm.