S100A9 and hypertriglyceridemia: The conclusion that TLR4 in the KCs mediates the ketone/lipid improving action of S100A9 is strongly supported by the fact that re-expression of TLR4 in KCs of ID mice is sufficient for virtually all of the hyperketonemia- and hypertriglyceridemia-lowering effect of S100A9 (Fig. 4B-4E).