G2A has been shown to regulate proliferation, immune function, oncogenesis, and other important biological pathways, and it shares substantial homology with three other GPCRs including G protein-coupled receptor 4 (GPR4), ovarian cancer G protein-coupled receptor 1 (OGR1/GPR68), and T cell death-associated gene 8 (TDAG8) [33,34]. Here, GPR4 is linked to ovarian carcinoma.