The role of NOD2 in adaptive immunity was also confirmed by in vivo experiments in mice, insofar as Nod2−/− mice infected with Mtb and treated with BCG produced fewer Th1‐type cytokines and showed reduced recruitment of CD8+ and CD4+ T cells in the later phase of the infection than wild‐type mice, and had a higher mortality rate [135]. This evidence concerns the gene NOD2 and infection.