BRS3 and carcinoid tumor: Brs3 mRNA and/or immunoreactivity is present in the CNS, but it is reported that BRS-3 is also found in peripheral sites, including muscle, islet beta cells, testis, ovary, uterus, lung, and cancers including carcinoid/neuroendocrine [5], [20], [21], [22] (https://gtexportal.org/home/gene/BRS3).