Upregulation of cytotoxic machinery in ILC3s upon IL-12 and IL-15 exposure. Splenic NKp44⁺ ILC3s were cultured for 4 weeks with IL-2 and IL-7 or IL-12 and IL-15 and stimulated for 4 hours with K562 target cells or PMAi. (A) Flow cytometric analysis (top) and quantification (bottom) of total GzmB or perforin expression in cultures. Fluorescence-activated cell sorting (FACS) plots shown for unstimulated expanded ILC3s and NK cells. Red lines show mean and box-and-whiskers plot extend min to max with black lines representing median value. (B) Degranulation of bulk cultures. Δ%CD107 indicates the difference in degranulation with and without K562 coincubation. N = 6 (3 HFL donors, 4 mice per donor). ns, P > .05; *P < .05; **P < .01; ***P < .001 using the paired Student t test.