IL33 and infection: The number of eggs per worm pair, calculated by dividing the raw number of worm pairs by the raw number of tissue (liver and intestinal) eggs, seemed to be comparable between IL-33−/− and WT mice during the whole course of infection (t(5) = 0.184, P = 0.861; t(9) = 1.972, P = 0.081; t(3) = 0.919, P = 0.423, at 6, 9 and 12 wpi, respectively; Additional file 1: Figure S1a).