where are b cells made
In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricius, a lymphoid organ. (The B from B cells comes from the name of this organ, where it was first discovered by Chang and Glick, and not from bone marrow as commonly believed). B cells, unlike the other two classes of lymphocytes, T cells and natural killer cells, express B cell receptors (BCRs) on their cell membrane.