Thiol protease which cleaves IL-1 beta (il1b), releasing the mature cytokine which is involved in a variety of inflammatory processes, and mediates apoptosis. Component of the NLRP1 inflammasome, which plays a crucial role in innate immunity and inflammation. In response to pathogens and other damage-associated signals, recruited to the NLRP1 inflammasome in its precursor form. Its subsequent activation causes the cleavage of pro-il1b into the midformed il1b, which then evetually leads to il1b maturation and secretion in the extracellular milieu. Required for the development of the cartilaginous pharyngeal skeleton