LYZ and infection: We therefore examined the expression of antimicrobial peptides such as RegIIIγ, RegIIIβ, lysozyme, cryptdin, Pla2g5 and Pla2g2a in the gut of control and Stat3ΔIEC mice, under unchallenged conditions and after infection with C. rodentium. Interestingly, unchallenged Stat3ΔIEC mice lacked expression of RegIIIγ and RegIIIβ in the gut and showed significantly decreased transcription of Pla2g5 compared to unchallenged control mice (Fig. 4a).