PIGF and glioma: Therefore, it may be hypothesized that the secretion of cytokines like Rantes, PIGF, SDF1, IL-2 and IL-15 by Delta-24-RGD-infected glioma cells might shed new light to the proliferation and influx of immune cells recently observed in glioma tumors treated with Delta-24-RGD-based oncolytic adenovirus [57].