LPAR3 and cancer: In this review, we discuss a thorough overview of the role of GPCRs in cancers and their signaling mediators such as protease-activated receptors (PARs), chemokine receptors, Gα12/13 proteins, lysophosphatidic acid (LPA), GPCR-mediated signaling pathways including the Wingless and Int-1 (WNT) and Hippo signaling pathways, and the cross-talk between GPCRs and other receptors that can lead to signaling circuit transactivation.