KLRK1 and Kaposi's sarcoma: For example, Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) downregulates the expression of MHC class I on KSHV-infected cells to avoid being recognized by MHC-restricted CD8+ T cells, which renders these cells susceptible to being killed by NK cells through the induction of NKG2D-mediated activating signaling 58.