IL1B and infection: The current study was undertaken to further evaluate the innate immune response to M. tuberculosis, specifically the expression of VDR on macrophages and the production of IL-1β by macrophages in in vitro experimental conditions that simulate in vivo infection with M. tuberculosis. Differential expression of VDR and IL-1β could provide new insights into TB pathogenesis and help identify those persons at increased risk of progression from latent M. tuberculosis infection to active TB disease.