On theother hand, the observation that the production of CXCL-10 was notaffected by the addition of IL-4 could be ascribed to theactivation of the NF-κB pathway induced by the directinteraction of M. bovis with the human epithelial cells,since it has been demonstrated that the infection of cells bymycobacteria stimulated a rapid binding of NF-κB to theκB site within the CXCL-10 gene promoter [25]. Here, IL4 is linked to infection.