RXFP1 and systemic sclerosis: Meanwhile, a recent study on RLX in scleroderma showed that the expression of RXFP1 on the surface of fibroblasts in patients with scleroderma was reduced, thereby reversing the anti-fibrotic effect of RLX in systemic scleroderma, and Corallo et al. (2019) found that RXFP1 was normally expressed in normal fibroblasts and RLX could counteract TGF-β1-driven upregulation of α-SMA via RXFP1.