HMOX1 and infection: Indeed, our results indicate that the increase of the mRNA levels of nrf2, a transcription factor responsible for the regulation of cellular redox balance and protecting antioxidant responses [46,47], is accompanied by an increase in some antioxidant enzyme genes, demonstrating that the infection, HO-1, Tregs, and the Nrf2 master regulator comprise a complex axis of antioxidant and immunoregulatory properties in F. hepatica infection.