These cells express T lymphocyte markers and the natural killer cell receptor NKG2D (NK group 2, member D), through which they recognize and kill cells expressing the stress-associated ligands MHC-class-I-polypeptide-related sequences A and B (MIC A and MIC B), which are expressed in the tumor microenvironment and after viral infection [38]. The gene discussed is KLRK1; the disease is viral infectious disease.