On the other hand, in some reports, the in vitro infection of macrophages by Leishmania was shown to promote the synthesis of IL-10, IL-6, TNF-α, and/or their correspondent mRNA, even in the presence of subphysiological concentrations of sera lipoproteins, that is, the concentrations present in a medium containing 10% normal serum [33–37]. This evidence concerns the gene IL6 and infection.