EFNA1 and glioblastoma: Reciprocally, even if other EphA4 ligands, such as Ephrin-B2 and Ephrin-A1, have been respectively shown to exert pro- and anti-oncogenic effects in glioblastoma occurrence and angiogenesis regulation, we failed to observe any significant change in Ephrin-A1, -A2, -A3, -A4, -A5 and -B2 expression upon invalidation of Ephrin-B3 in the tumor xenograft model used here, thereby strengthening the specificity of the effects observed (Supplementary Figure 3D).