Blood cells carry a deep evolutionary history. A new analysis suggests their earliest ancestors were macrophage-like cells inherited from single-celled life.

A new evolutionary analysis suggests that modern blood and immune cells may preserve a 700-million-year legacy inherited from ...

Almost all animal species—including humans—have blood cells, but between different species our blood tells different stories.

Red blood cells transport oxygen throughout your body, including to vital organs and tissues. They also help your body get rid of carbon dioxide. Too little or too many red blood cells may be ...