Both cell types: (i) kill tumor cells in a MHC-independent manner (34), (ii) are involved in anti-CMV immune responses (67), (iii) do not mediate GvHD, since they do not recognize peptide antigens presented in the context of MHC (12), (iv) interact with each other and with additional immune cells, such as αβ T-cells and dendritic cells (12), and (v) following activation, are cytotoxic to mesenchymal stromal cells, a major component of tumor microenviroment (68). This evidence concerns the gene HLA-C and neoplasm.