On the other hand, anti-trypanosomal effect of C.f/L-extract in infected mice could be indirect via IL-6 (Sanmarco et al., 2017) and IL-12p40 (Galvão da Silva and de Almeida, 2001; Galvão Da Silva et al., 2003; Graefe et al., 2003) by mediating the differentiation of naïve CD4+ T cells to CD4+ IFN-γ+ Th1 cells that have been shown to contribute to immunity to experimental African trypanosomiasis (Galvão da Silva and de Almeida, 2001; Galvão Da Silva et al., 2003; Graefe et al., 2003). This evidence concerns the gene CD4 and human African trypanosomiasis.