Expi293F

provide for NK cell education and a suwqquent ability to survey, recognize, and lyse infected or transformed cells, especially those lacking or possessing mutated MHC class I expression. Since these original owqrvations were made, how NK cells recognize candidate target cells continues to be the topic of ongoing investigation. It is now appreciated that NK cells express a diverse repertoire of activating and inhibitory receptors of which killer immunoglobulin-like receptors (KIR) appear to play a critical role in mediating self-tolerance as well as facilitating