B cells are a vital component of the adaptive immune response that, along with T cells, respond to harmful pathogens and establish immunological memory within the organism. B cells are defined by their expression of clonally diverse cell surface and secreted immunoglobulin B cell receptor (BCR) molecules. B cell development is initiated in the fetal liver and in the bone marrow in adults; however, subsequent functional maturation occurs in secondary lymphoid tissue. Early in development, the pre-BCR plays a pivotal role in assuring the continued maturation and survival of B cell progenitors.
Learn more about B cells in our B Cell Knowledge Center.