TLR4 and hereditary spastic paraplegia: In addition, the mRNA expression levels of TLR4 (1.53±0.58, n=105) in all the patients with HSP (groups A, B, and C) exhibited a positive correlation with the level of TLR4 protein expression (0.30±0.17, n=105; r=0.61, P<0.01) (Fig. 2).