Similar results were obtained on the protein level: the IL-1β protein level increased only slightly but not significantly in wild-type mice fed a NASH-diet but by contrast, a significant two-fold increase in IL-1β protein was observed in NASH-diet-fed mPGES-1-deficient mice (Fig. 4D, original blots in Supplementary Figure S5). Here, IL1B is linked to metabolic dysfunction-associated steatohepatitis.