The intracellular levels of the cysteine protease caspase-1 (accession no. P29466), which activates itself and converts the immature pro-IL-1β into its mature form after recruitment by the inflammasome complex (40), were found to be enriched in THP-1 macrophages upon infection with all rickettsial species (Fig. 7B). The gene discussed is IL1B; the disease is infection.