GPR68 and ovarian carcinoma: GPR68, also known as ovarian cancer G protein-coupled receptor 1 (OGR1), is a member of the proton-sensing G protein-coupled receptor (GPCR) family that contains three additional members: GPR4, GPR65 (or T lymphocyte death-associated gene 8 protein, TDAG8), and GPR132 (or G2 accumulation protein, G2A).