Finally, the E6/E7-dependent LEDGF expression may not only promote tumor growth by protecting HPV-positive cancer cells against different forms of cellular stress, but also could contribute to tumor progression and metastasis more directly, e.g. by enhancing the formation of blood and lymph vessels, as reported for the LEDGF-mediated activation of VEGF-C in glioma, lung cancer and ovarial cancer models [24], [26]. This evidence concerns the gene PSIP1 and glioma.