Fig. 3 showed that HMVEC-d constitutively expressed C3aR and CD88 (isotype control vs medium only). Moreover, the endothelial expression levels of both C3aR (Fig. 3A) and CD88 (Fig. 3B) were not significantly affected by the incubation with plasma of patients with acute HSP (HSP plasma vs control plasma, C3a: 11.9 ± 0.6 vs 13.2 ± 2.4, p = 0.56; C5a: 25.5 ± 4.1 vs 24.3 ± 0.3 ng/ml, p = 0.65). Here, C3AR1 is linked to hereditary spastic paraplegia.