Somatostatin exerts its biologic effects by binding to specific high-affinity receptors, which appear in many cases to be coupled to GTP-binding proteins.the human medullary thyroid carcinoma cell line TT , expresses all SSTR subtypes; that SSTR2 activation inhibits DNA synthesis and cell proliferation, whereas SSTR5 activation increases DNA synthesis; and that an SSTR2 preferential agonist can antagonize SSTR5-selective agonist action, and vice versa. These findings suggest a tissue-specific function and a tissue-specific interaction between the 2 receptors.the prognostic information derived from SSTR2 is apparently independent from MYCN amplification, as assessed by stratifying SSTR2 values according to MYCN. The authors concluded that SSTR2 expression represents a prognostic marker for neuroblastoma.