Endothelin-3, human, mouse, rabbit, rat TFA is a 21-amino acid vasoactive peptide that binds to G-protein-linked transmembrane receptors, ET-RA and ET-RB.

H-Gly-Ile-2-Nal-Trp-His-His-Tyr-OH

SI-2 is an inhibitor (SMI) of steroid receptor coactivator-3 (SRC-3 or AIB1). SI-2 can selectively reduce the transcriptional activities and the protein concentrations of SRC-3 in cells, and selectively induce breast cancer cell death with IC50 values in the low nanomolar range (3-20 nM), but not affect normal cell viability.