Conjugatable ligands are designed to enhance the immune response by targeting specific receptors or pathways. They are chemically modified to allow attachment to a peptide or protein using a chemical linker, thereby enhancing stability, bioavailability, and targeting precision. Conjugatable ligands mainly include cytosolic pattern recognition receptors (PRRs), C-type lectin receptors (CLRs), Toll-like receptors (TLRs), PRR agonists, and toxoid adjuvants. Developing conjugatable ligands that target various immune receptors is essential for effective targeted therapies and vaccine delivery systems.