TNFSF4 and infection: We further confirmed that expression of IL-12 mRNA was equally upregulated by DCs from CD11ccre × OX40Lf/f and OX40Lf/f littermate controls after infection with Lm-2W1S (Supplementary Fig. 4), indicating that IL-12 production by OX40L-deficient DCs was not impaired and the loss of Th1 effector cells not due to impaired polarisation during priming.