CXCL9 and hereditary spastic paraplegia: HSP pooled from HIV positive individuals (a) compared to HSP pools from fertile (b) and random (c) donors, showed statistically significant higher concentrations of TGF- ß1 ((b) p = 0.0001, (c) p = 0.0001), IL-1ß ((b) p = 0.0021, (c) p = 0.0061), IFN-γ ((b) p = 0.0004, (c) p = 0.0004), CCL3 ((b) p = 0.0035, (c) p = 0.0001), CCL5 ((b) p = 0.0002, (c) p = 0.0009) and CXCL9 ((b) p = 0.0001, (c) p = 0.0001).