The field is currently hampered by lack of knowledge about endogenous ligands and downstream signaling for aGPCRs. Once this knowledge gap is overcome, a clear library of agonists and antagonists can be developed, unleashing successful and widespread aGPCR exploitation and modulation. In the coming years, ligand identification will accelerate, allowing more aGPCR therapeutic advances.
Stillwell et al. (2026) studied this question.