NK cell hyporesponsiveness in IL-12/23 axis–deficient patients. (A) A representative experiment comparing the in vitro reactivity of NK cells from healthy control individuals and IL-12Rβ1–deficient patients is shown. PBMCs were incubated for 4 hours in the presence or absence of K562 cells and assessed for CD107 and IFN-γ expression. (B) PBMCs prepared from a cohort of healthy control individuals, IL-12Rβ1–deficient patients and one IL-12p40–deficient patient were analyzed for their NK reactivity in the presence of indicated tumor cells; ADCC: antibody-coated P815 cells. Values indicate mean plus or minus SD. Each dot represents the data obtained from one individual.