Relaying of a signal by conversion from one physical or chemical form to another. In cell biology, the process by which a cell converts an extracellular signal into a response.
The cascade of processes by which a signal interacts with a receptor, causing a change in the level or activity of a second messenger or other downstream target, and ultimately effecting a change in the functioning of the cell.
![Adult](JavaScript:void
window.open("/cgi-bin/rnaidb/popUpImage.cgi?imgName=N2wormfinal.png",
"RNAiDB Help","toolbar=no, location=no, directories=no,
status=no, menubar=no, scrollbars=yes, resizable=no,
copyhistory=no, width=1000, height=550"))
