Second in a two-part series on mitochondria. See part 1.

Recent advances in single-cell genomics have made it possible to study individual cells and learn how they develop into specialized cells. However, we have only limited information on cells’ origins and how they’re related to the other cells around them.

Meanwhile, efforts to understand more about how cells differentiate and divide have looked at whole cell categories at a time, offering little knowledge of individual cells.

“It’s like looking at the statistics for a college — you can determine what the average student is like, but you have no idea what any one individual student is doing,” says Vijay Sankaran, MD, PhD, a hematologist at Boston Children’s Hospital. “Learning about cellular relationships is critical — it can help us understand how many stem cells give rise to any tissue in our body, what cell types cancers emerge from, or how some cells can be dysfunctional in particular diseases.”