We found that inhibition of SDF-1 and CXCR4 in L-CSCs blocks the in vitro proliferation of these cells upon basal conditions, indicating that autocrine activation of SDF-1 signaling promotes L-CSCs proliferation/survival, as previously reported in glioblastoma CSCs [23, 41]. The gene discussed is CXCR4; the disease is glioblastoma.