KLRK1 and neoplasm: Several studies have shown the accumulation of CD11b+Gr1+ MDSCs in the spleen of tumor-bearing mice resulting in reduced NK cell cytotoxicity by either down-regulating the expression of activating receptors NKG2D, NKp30 or by reducing the production of IFN, perforin (Bruno et al., 2019; Greene et al., 2020; H. Li et al., 2009).