Blood includes many different kinds of cells, he said, while insulin is a protein.
You find them in all kinds of cells, not just nerve tissue.
"With this model, you can see how different kinds of cells respond to the drugs."
There are some kinds of cells whose main job is to make hormones.
A few kinds of cells, however, are large enough to be seen with the unaided eye.
There are two kinds of reproductive cells produced by flowers.
Eventually there are two hundred and fifty different kinds of cells, all developing together, at exactly the right time.
"It turned out that we were looking at many kinds of cells," she said.
It is specific only to certain kinds of cells.
Even though there are many kinds of cells, they have some similarities too.