Liu et al. (2010) showed that tree shrews are resistant to atherosclerosis because of low cholesteryl ester transfer protein expression and low phospholipid transfer protein activities. Li et al. (1999a) induced thrombotic cerebral ischemia in tree shrews using a photochemical approach, with Feng et al. (2011) showing that cerebral ischemia caused a predominant increase in TLR4 protein expression in the tree shrew hippocampus. A blood stasis syndrome model was also successfully established in tree shrews with high-dose carrageen glue (Zhang et al., 2016). Here, TLR4 is linked to Cerebral ischemia.