When Robert Hooke peered through a primitive microscope in the mid-17th century, he set in motion a revolution. Today’s understanding of the fundamental structure of living organisms began when he examined thin slices of cork and saw tiny walled compartments that looked like a monk’s dwelling: He called them cells.
Subsequent advances over the centuries deepened our understanding of these structures, which we now know to be the basic unit of life. In the past decade alone, quantum leaps in technology have enabled scientists to explore the Lilliputian universe of the cells with unprecedented precision. The developments have sparked the creation of a massive scientific juggernaut that rivals the Human Genome Project in scope and importance.
Called the Human Cell Atlas (HCA), the international research effort aims to create a comprehensive 3D reference map of how genes are expressed, or activated, in different cell types and their states in every organ system of the human body. The global consortium includes more than 1,000 scientists from 584 institutes in 55 countries. While they won’t attempt to plumb all 37 trillion cells in the human body, initial research is zeroing in on five main areas, including cancer; the brain and nervous system; the immune system; the epithelial tissues that serve as a protective layer throughout our body; and human development, starting with cell differentiation in the womb.
The work has the potential to usher in a new era of precision medicine that will transform our understanding of health and disease, leading to better detection, monitoring and treatment of the ills that plague humanity. “There’s much more diversity in the cells than we previously imagined, and there has been an explosion in technology that is shedding light on that,” says Sarah Teichmann, head of cellular genetics at the U.K.’s