Scientists launched a global initiative to map out and describe every cell in the human body in a vast atlas that could transform researcher's understanding of human development and disease. The atlas , which is likely to take more than a decade to complete, aims to chart the types and properties of all human cells across all tissues and organs and build a reference map of the healthy human body, the scientists said. Cells are fundamental to understanding the biology of all health and disease , but scientists can not yet say how many we have , how many different types there are, or how they differ from one organ to another . "The human cell atlas initiative is the beginning of a new era of cellular understanding ,"Sarah Teichmann , head of cellular genetics at Britain's Sanger institute told. "We will