This article dives into the fascinating journey of B cells, the immune system’s antibody factories, from their origins in bone marrow to their full maturation. It breaks down the complex steps—like gene rearrangement and signaling pathways—that shape these cells into defenders against pathogens, comparing the process in mice and humans. Think of it as a behind-the-scenes look at how your body builds its microscopic army.

Editor’s Note: Understanding B cells isn’t just academic—it’s key to grasping how vaccines work, why some people get autoimmune diseases, and how cutting-edge therapies (like those for cancer) harness the immune system. For anyone curious about why we don’t get sick constantly, this is a peek under the hood of our biological defense system.