Cytokines
Cytokines are tiny proteins that cells send out to tell other cells what to do.
Think of it this way
In a busy kitchen, the head chef sends out small notes to every station. Each note tells a worker to speed up, slow down, or change what they are cooking. The notes travel fast and reach many stations at once. This keeps the whole kitchen working as one team.
Explaining cytokines by grade level
Your body has tiny helpers called cytokines. They are like notes that cells pass to each other. When you get a cut, cells send out these notes. The notes tell other cells to come help fix the cut. Some notes say to start healing. Other notes say to stop when the job is done.