“…NK cells express acti-vating receptors such as CD16, NKp30, NKp44, NKp46, NKp80, NKG2D, CD244, CD226; cytokine receptors such as IL-2R, IL-28R, IL-12R, IFNR, IL-15R, IL-18R, IL-1R8, IL-10R, and TGFβR [58,62]. The inhibitory receptors expressed by NK cells include NKG2A, KLRG1, KIRs, TIGIT, TIM3, Siglecs, PD-1, LAG3, A2AR, LAIRs, and ILTs [58,63]. Under homeostatic conditions, human circulating NK cells represent about 5-15% of circulating lymphocytes and are subdivided into two main subsets defined based on their differential expression of CD56 and CD16, namely CD56 bright CD16 − and CD56 dim CD16 + [64,65].…”