In contrast to the class II pathway, genes involved in antigen processing and presentation via the MHC class I pathway (i.e., β2-microglobulin, tapasin, HLA-C, HLA-F and HLA-G) were not altered by parasite infection at 24 h, except for HLA-B and calnexin genes, which were down-regulated, and HLA-A, which was up-regulated. This evidence concerns the gene HLA-B and parasitic infectious disease.