PYCARD and obesity due to melanocortin 4 receptor deficiency: Finally, metabolic disturbances during obesity seems to interact with low-grade inflammation, and as shown in Figure 3G, IL-18 levels were significantly elevated in obese WT mice, but remained unchanged in HFD fed Nlrp3−/− and Asc−/− (Pycard−/−) mice (Figure 3G), using an assay which detects only the mature form of IL-18.