TNF and infection: The aim of this study was to evaluate the gene expression of regulatory cytokines (IL-10 and TGF-β), proinflammatory cytokines (TNF-α and IL-1β), the transcription factor Foxp3 at different levels (gene and antigenic expression), and portal fibrosis in liver tissue samples from unimmunized and immunized (recombinant cathepsin L1 -FhCL1) sheep during early stages of the infection with F. hepatica.