The role of these cytokines in Mycobacterium infections has not only been confirmed in the simplistic microenvironment of in vitro settings, but also in in vivo studies, as both TNF and IL-1β KO mice are extremely sensitive to M. tuberculosis infection [76], and an increase in the expression of both cytokines has been described in intestinal tissues of paratuberculosis infected sheep [77]. Here, TNF is linked to Mycobacterium infection.