Definition

An agonist of the intracellular innate immune adaptor stimulator of interferon genes protein (STING; transmembrane protein 173; TMEM173), with potential immunoactivating and antineoplastic activities. Upon intratumoral administration, STING agonist MK-2118 targets and binds to STING and activates the STING pathway in immune cells in the tumor microenvironment (TME). This leads to the production of pro-inflammatory cytokines, including interferons (IFNs), enhances the cross-presentation of tumor-associated antigens (TAAs) by dendritic cells (DCs), and induces a cytotoxic T-lymphocyte (CTL)-mediated immune response against cancer cells. STING, a transmembrane protein that activates immune cells in the TME, plays a key role in the activation of the innate immune system.