They interact closely in tumor growth and progression [35], and our study also showed that they strongly interact with each other: an increase in the concentration of VEGF-A induced a decrease in the concentration of FGF-2, while a decrease in the concentration of VEGF-A caused an increase in the concentration of FGF-2, as is clearly observed when analyzing the concentrations of these growth factors in the control group for brain glioma. Here, FGF2 is linked to brain glioma.