Cell signaling can trigger a wide range of outcomes, from small and simple to large and complex. These can happen at the invisible molecular level or the visible, large-scale macroscopic level.
Examples of outcomes at a molecular level include increase in transcription of certain genes or increase in activity of a particular enzyme.
Examples of outcomes at a macroscopic level may include changes in outward appearance of the cell (such as cell growth or cell death) or the manner in which it behaves.
A cell signaling pathway may activate a single molecular event or a series of molecular events, producing a larger outcome.
For example, growth factor signaling triggers an array of molecular changes that results in the larger outcome of growth and division (cell proliferation).
Changes in cell identity, cell migration, and induction of programmed cell death or apoptosis, are some of the more notable large-scale outcomes of cell signaling.