GPR97 (ADGRG3) is a G protein-coupled receptor that modulates NF-kB activity in the spleen, regulates B-cell development and maintain B-lymphocyte populations. It also functions to regulate antimicrobial activity in granulocytes. GPR97 has high membranous positivity on subsets of lymphocytes in immune tissues, on some neuroendocrine cells in various tissues, and on some neurons in the cortex, hippocampus, hypothalamus, caudate, putamen, thalamus and basal nucleus of Meynert in the central nervous system. GPR97 also has faint or greater positivity on tumor cells in a range of cancers. References: Front Immunol. 2018 Dec 3;9:2830, PMID: 30559745; Cell Death Dis. 2013 Oct 10;4:e853, PMID: 24113187;