The mRNA level of HO-1 increased noticeably after 3 h of infection following NaHS treatment (8.5 versus 1.15 fold in treated versus not-treated, respectively) (p ≤ 0.005) while the effect of H2S on the mRNA level of HO-1 was less noticeable at late time points (18 and 24 h) (Fig. 1b). This evidence concerns the gene HMOX1 and infection.