STAT1 and cerebrotendinous xanthomatosis: In our case, although the number of infiltrated inflammatory cells didn't obviously increase in STAT1−/− mice, the cytokines secreted by these inflammatory cells (e.g., TNFα and IL-1β) were significantly higher in STAT1−/− mice at early time points (1 day or 2 days after CTX injury), suggesting that the expression of these inflammatory factors may be regulated directly or indirectly by STAT1.