Constitutively expressed cytokine receptors on NK cells. Common gamma chain (γ_c) receptors constitutively expressed by NK cells include intermediate affinity IL-2/IL-15 (βγ_c) receptor. High-affinity IL-15Rα is presented in trans by other cell types. CD56^bright NK cell subsets constitutively express high-affinity IL-2Rα and IL-7R, CD56^dim NK cells upregulate these receptors upon activation. IL-12R is constitutively expressed and required for adaptive memory responses. TGFβR inhibits IL-15R signal transduction and significantly alters NK cell phenotype and effector functions.