Vorbipiprant (CR6086) is an orally active EP4 receptor antagonist with high selectivity for the human EP4 receptor (Ki: 16.6 nM) . Vorbipiprant has immunomodulatory, anti-inflammatory, antitumor, and anti-angiogenic activities. Vorbipiprant can inhibit the expression of multiple pro-inflammatory cytokines and the activation of immune cells, and convert "cold" tumors unresponsive to immune checkpoint inhibitors into "hot" tumors. Vorbipiprant is used in the research of diseases such as rheumatoid arthritis and colon cancer[1][2].