Researchers have demonstrated a promising new approach to delivering immunotherapy agents to fight cancer. The approach involves tethering an immunotherapy agent called a STING agonist to an acid-seeking molecule called pHLIP® (pH-low insertion peptide). The pHLIP molecules target the high acidity of cancerous tumors, delivering their immunotherapy cargo directly to cells in the tumor microenvironment. Once delivered, the STING agonists engage the body’s innate immune response to fight the tumor.