In addition, MDD patients have increased expression of NLRP3 and caspase-1 in circulating immune cells, suggesting that the NLRP3 inflammasome is activated in MDD patients, which correlates with increased levels of IL-1β and IL-18 in MDD patients (Alcocer-Gomez et al., 2014). Here, CASP1 is linked to major depressive disorder.