+A second messenger is a small, non-protein molecule that relays and amplifies signals within a cell. These crucial molecules transduce information from [Receptors](/wiki/receptor) on the cell surface, orchestrating diverse [Cellular Responses](/wiki/cellular_response) inside. They are vital for intercellular communication and signal cascades.
+## See also
+- [Cell Signaling](/wiki/cell_signaling)
+- [Cyclic AMP](/wiki/cyclic_amp)
+- [Protein Kinase](/wiki/protein_kinase)