IDO2 and metabolic dysfunction-associated steatohepatitis: Although the activating factors Il2, Il12b, Il15, Cxcl9, and Cxcl10 of NK cells showed upregulated trend in the NASH-FMT group (Figure 6a–f), the inhibitory factors Tgfb1, Il10, and Ido2 also showed upregulated trend (Figure 6g–i), which may be one of the reasons why it leads to NK cell immune tolerance.