In zebrafish, we isolated ECs (GFP-positive, 2.2% of whole cell population) from Tg(flk:egfp) zebrafish endogenous glioma before active blood circulation occurs and detected the expression of IL-6, IL-8, FDF2 and SDF-1 by using quantitative RT-PCR. Here, CXCL12 is linked to glioma.