Chemokines, chemokine receptors, ligands , motif chemokines and cytokines are supplied by MyBioSource in 1.Cytokines and Chemokines are chemotaxis related small proteins between 5 to 20 kDa.FAS ligand and other ligands are binding to the receptor for signaling pathways for example in apoptosis or JNK signaling. Receptor agonists are often tested for drug development.Peptides short amino acid chains or epitopes or blocking antagonists. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetra peptides, ... till polypeptides that are long, continuous, and unbranched synthetic peptide chains. These biological oligomers and polymers can be Solid-phase peptide synthesis (SPPS), or in continue produced for custom peptide synthesis projects. The High-efficiency solid phase peptide synthesis (HE-SPPS) is give very low production costs.