PDK4 and influenza: Based on our new findings, together with the growing evidence of interrelation between cytokines and metabolic disorders [30]–[32], interrelation between cytokines and PPARs [33], [46], [50], and interrelation between PPARs and metabolic disorders through PDK4 [50]–[52], we propose a new concept of host cellular mechanism for MOF in severe influenza (Figure 10).