Studies by Alural et al. showed that the acquired resistance and survival of GBM upon erythropoietin (EPO) treatment is mediated by MMP-2, MMP-9, VEGF, C-X-C chemokine receptor type 4 (CXCR4), Bcl-2, survivin, and Akt. The gene discussed is BIRC5; the disease is glioblastoma.