To assess the impact that this oxygen heterogeneity might have on the different MB groups, we analyzed the expression of 19 HIF-1 target genes (Tf, Ho1, Ccl2, Oas2, Lox, Igf2, Slc2a1, Epo, Il2ra, Gpnmb, bFgf, Ak3, Hk1, Myl3, Cxcl16, Igfbp2, Murc, Des and Ccl5) from the Affymetrix Human Gene 1.1 ST array profiling of 763 primary medulloblastoma samples (GSE85217) [31]. The gene discussed is EPO; the disease is medulloblastoma.