Dopamine blocks stress-mediated tumor growth and tumor endothelial pericyte coverage by activating pericyte dopamine receptor 1 (DR1) cAMP/PKA signaling pathway (64).Dopamine receptor 2 (DR2) and hypoxia-inducible factor-1a (HIF1a) were highly expressed in tumor nuclei in stressed-induced tumor-bearing mouse models. This evidence concerns the gene DR1 and neoplasm.