Additionally, the mRNA expression levels of VEGF (-A/B/C), bFGF, placental growth factor (PLGF), angiopoietin 1 (ANG1), angiopoietin 2 (ANG2), PDGFB1, EGF, TNF-α, transforming growth factor-α (TGF-α), transforming growth factor-β (TGF-β), IL8, PF4, TSP1, vascular endothelial receptors 1 and 2 (VEGFR1 and VEGFR2) were determined within low- and high-grade CC-RCC and correlated with immunohistochemical (IHC) angiogenesis data. Here, FLT1 is linked to renal cell carcinoma.