How do you define "cellular level"?

The cellular level is the level of cells, the most basic structural units of the human body. Just like a house is made of many individual bricks sealed together by cement, the human body is comprised of millions of cells that combine to form tissues, organs and whole organisms.

It is essential that a cell is able to respond to its environment and communicate with surrounding cells to regulate both its own activities and the actions of its neighbor. Scientific research at the cellular level is providing new insight into the most devastating human diseases, such as cancer, heart disease and diabetes.