In addition to β2ARs and A2BRs, a few other Gs-coupled GPCRs including prostaglandin E2 receptor 4 (EP4), prostacyclin receptors (IP), calcitonin receptor-like receptors (CLRs), and relaxin receptors (LGR7) have been shown to inhibit cardiac fibrosis (Figure 1). Here, PTGIR is linked to fibrosis.