GPR68 and ovarian cancer: Thus, other putative lactate sensors GPR4, GPR65 (TDAG8), GPR68 (also known as ovarian cancer G protein-coupled receptor 1, OGR1), and GPR132 (G2A) have been described as proton sensitive and could be involved in immune modulation during the inflammatory processes characterized by low pH levels obtained from lactic and carbonic acids (166, 169).