An analysis of post-mortem tissue from sporadic ALS patients showed a increased TLR4 expression in the spinal cord,299 and immunostaining revealed that TLR4 is mainly expressed in astrocytes located in the white and gray matter of cervical spinal cord tissue from ALS patients.308 In the hSOD1 G93A transgenic mouse model, the expression of TLR4 was upregulated in microglia and astrocytes, and TLR4 deficiency or antagonist treatment decreased microglia activation, improved motor function and extended life expectancy.309,310. Here, TLR4 is linked to amyotrophic lateral sclerosis.