When Mycobacterium tuberculosis infects humans, about 20% of those infected actually develop tuberculosis. In Japan, the incidence of tuberculosis in 2008 was 19.4/100 000 persons (24 760 cases) and the rate has been decreasing gradually , but is still higher than that in the USA, Holland , and Belgium, for example. Histologically, experimental tuberculosis displays exudative inflammation , proliferative inflammation and productive inflammation depending on the time course. In productive inflammation , granulomatous lesions with necrotic centers are formed. The typical granulomas consist of epithelioid macrophages, Langhans' multinucleated giant cells, lymphocytes and fibroblasts , and the process of their formation involves many cytokines, chemokines and transcription factors. These findings have been derived primarily from animal experiments utilizing an airborne infection apparatus. This review focuses on the basic research aspect of tuberculosis-what has been found through animal experiments by our research group-and furthermore , indicates what we should do in tuberculosis research in the near future.