EP4 antagonist 14 is a prostaglandin E2 receptor subtype EP4 antagonist, demonstrating an IC50 of 1.1 nM in a HEK293 human receptor reporter assay and blocking β-arrestin recruitment due to PGE2 with an IC50 of 0.9 nM. At 10 µM, it reduces PGE2-stimulated mRNA levels of Il-4, macrophage mannose receptor 1 (Mrc1), chitinase-like protein 3 (Chil3), chemokine (C-X-C) motif ligand 1 (Cxcl1), triggering receptor expressed on myeloid cells 2 (Trem2), and arginase-1 (Arg1) in RAW 264.7 macrophages. When used at 30 mg/kg per day alongside anti-PD-1 antibodies, it curbs tumor growth and enhances CD8+ T cell infiltration in tumors using a CT26 murine colon cancer model.

Saralasin acetate is a Non-selective angiotensin II antagonist.

PDC31 (THG113.31; ILGHXDYK) is a D-amino acid-based oligopeptide that acts as an allosteric and non-competitive inhibitor of the FP Prostaglandin Receptor, used primarily as a smooth muscle contractile agent. It effectively reduces the strength and duration of uterine contractions in vivo, offering potential for preterm labor and primary dysmenorrhea (PD) research. Additionally, PDC31 enhances the Ca2+-dependent large-conductance K+-channel in human myometrial cells [1] [2].