This evidence supports the activation of an autocrine/paracrine loop in GBM CSCs, in which the abundant production of IL-8 and GRO over-activates and then down-regulates CXCR2 mRNA expression in standard culture conditions (paradoxically the lower levels of expression may reflect the higher activation of the pathway) whereas the receptor expression level increases only after the removal of chemokines from the medium (cell starvation). Here, CXCL1 is linked to glioblastoma.