Under the effect of several angiogenic stimuli such as vascular endothelial growth factor (VEGF) [57–59], certain hormones (e.g. oestrogen, progesterone and insulin) [60], and shear-stress [61], NO synthesis is induced via eNOS in ECs and activates specific signalling pathways leading to tumour angiogenesis and further metastasis (Figure 2). The gene discussed is NOS3; the disease is neoplasm.