IL18 and influenza: Interestingly, the magnitude of caspase-1 (p = 0.012) and IL-18 (p = 0.024) production in response to influenza + R848 was greater at Day 1 compared to baseline, while the opposite was true for IL-1β (p = 0.031) and pro-IL-1β (p = 0.024) secretion in response to influenza alone.