IL4 and infection: VHSV exposure resulted in a significant increase in IL-4/13B1 and B2 expression in the kidney during the early stages post infection (eg 1 to 5 days for IL-4/13B1, and 1-4 days for IL-4/13B2) that peaked at day 3 with a 26.3-fold increase for IL-4/13B2.