<prompt> Immunity against cancer cellsBasophilEosinophilsNK cellsNeutrophil  <response>: Ref Robbins 8EP 188;9e p192 NK cells kill virus- infected cells and produce the macrophage-activating cyto- kine IFN-g. If the microbes enter the blood, many plasma proteins, including the proteins of the complement system, recognize the microbes and are activated, and their products kill microbes and coat opsonize the microbes for phagocytosis. In addition to combating infections, innate immune responses stimulate subsequent adaptive immu- nity, providing signals that are essential for initiating the responses of antigen-specific T and B lymphocytes. 