SST and neoplasm: VEGF-A proteins also interact with neuropeptides in other tissues, such as somatostatin and angiotensin in the retina (Mei et al., 2012, Wilkinson-Berka, 2004) and kappa opioids in tumor angiogenesis (Yamamizu et al., 2013, Yamamizu et al., 2011) often through common downstream signaling pathways (Pan et al., 2008).