IRF1 and infection: Results showed that 6 out of 11 selected Th1-related genes, such as INFG, IRF1, SOCS1, STAT1, TNF and WARS, were significantly up-regulated at 48 hpi, while genes known to be predominately associated with Th2 response (IL4, IL13, MAPK14 and STAT6), were down-regulated or unchanged respectively at all time points during infection (Fig 4B).