protein processing signaling receptor ligand precursor processing https://github.com/geneontology/go-ontology/issues/19216 GO:0140448 signal maturation pg ligand maturation The cleavage of a peptide bond in a precursor form of a signaling receptor ligand, resulting in the mature (active) form of the ligand. GO:0035638 2020-04-03T13:30:04Z