Most notably, in recurrent glioblastoma patients, increased plasma protein levels of PlGF and IL-8 and decreased levels of bFGF and sTie-2 proteins were associated with partial radiological responses, whereas increased plasma protein levels of sVEGFR-1, sTie-2 and SDF-1a and decreased levels of PlGF correlated with radiological progression. The gene discussed is CXCL8; the disease is glioblastoma.