IE users: please get the latest browser version at Microsoft Internet Explorer Home Page
if yot already have the latest browser version please verify that your browser settings is not in compitabily mode
Immature B cells are precursors of B cells that have a critical role in prevention of auto-immune responses. In most mammals, they are produced in the bone marrow, where they are tested for auto-reactivity, and only then migrate to secondary lymphoid tissues (e.g. spleen, lymph nodes, etc.), where some of them differentiate into mature B cells.