DDN and glioblastoma: Moreover, other studies (again combining cranial and spinal GBMs) have shown that SPARC (secreted protein acidic and rich in cysteine) and VIM (vimentin) genes are over-expressed and CACNA1E (calcium voltage-gated channel subunit alpha1e), SH3GL2 (SH3 domain-containing GRB2-like 2, endophilin A1), and DDN (dendrin) genes are under-expressed in glioblastoma.