LPAR1 and breast cancer: Other studies have found that lysophosphatidic acid receptor 1 (LPA1), a metastasis-driving GPCR, upregulates oncogenic miR-21 via PI3K/ZEB1 to promote breast cancer invasion and bone colonization; miR-21 inhibition blocks LPA1-mediated migration and reduces metastatic burden in vivo (Sah et al., 2015).