Imagine an orchestra composed of 100 musicians, all playing a different instrument. Now consider what you'd hear if all of the musicians began playing a symphony, but with each starting on a different note, or playing in a different key.
If the individual members of the orchestra didn't communicate, their performance would probably sound like a cacophony of screeching tires and wailing animals--certainly not something you'd want to pay money to hear! Add a conductor with sheet music, and the outcome would be harmonious.
Like the musicians playing a symphony, living cells orchestrate their responses to external stimuli by synchronously altering their internal biochemistry. Cells react to messages received from a variety of sources, including hormones and cytokines, the two most powerful biochemical messengers in mammalian systems. Once a cell is stimulated by a messenger molecule, the biochemistry inside of the cell changes in a way that is meaningful to...