. "Viral protein involved in the modulation of host NK-cell activity. Natural killer (NK) cells are critical in defense against viral infections, since they provide host protection by releasing cytokines such as IFN-gamma or by direct lysis of infected targets. Therefore, during viral infections, viruses and NK cells are in a constant battle and many viruses have developed a variety of strategies to modulate NK cell activity." . . "Modulation of host NK-cell activity by virus" . .