KLRK1 and cancer: Rae-1–NKG2D interactions are not only implicated in cancer (Cipolat et al., 2014, Strid et al., 2008) but also mediate host responses to bacterial and viral infection (Hamerman et al., 2004, Lodoen et al., 2004, Strid et al., 2008, Strid et al., 2009).