RAF1 and neoplasm: HSP90 inhibition by geldanamycin can block tumour angiogenesis [46], [47], possibly by lowering VEGF-A production by tumor cells, reducing expression of VEGFRs in endothelial and lymphatic tissue [11] or modulating expression of master signaling regulators Akt and c-Raf [10] and subsequent nitric oxide production [34], [48].