B7-33

B7-33 is a single-chain synthetic analog of H2-relaxin created in 2016 as the first soluble relaxin analog. It selectively activates RXFP-1 receptors via the pERK pathway rather than cAMP, retaining anti-fibrotic properties while avoiding tumor-promoting effects. Research indicates applications in fibrosis, vasoprotection, preeclampsia, and cardiovascular studies.