IBSP and glioblastoma: BSP’s RGD sequence binds to integrins αv and αvβ3 on cancers cells to navigate cell migration and invasion.38,122,147,157,158 Similar to BSP-mediated adhesion, the RGD motif appears to be BSP-specific or requires full-length BSP, as recombinant human BSP induces greater encapsulated glioblastoma spheroid invasion than an RGD peptide.158 However, this RGD-dependence is partial, since a KAE-substituted recombinant human BSP fragment promotes breast cancer invasion similarly to its RGD-containing counterpart.122