IL1B and obesity due to melanocortin 4 receptor deficiency: The NLRP3 inflammasome complex is responsible for processing of both pro-IL-1 and pro-IL-18; nonetheless, NLRP3−/− mice are not prone to the development of spontaneous obesity (42), indicative that the NLRP3-inflammasome complex may not be responsible for processing of central pro-IL-1β or pro-IL-18 that likely maintains weight homeostasis.