They both proliferate, increase in number, and they differentiate; they differentiate from immature B-cells into antibody producing cells.

淋巴细胞将迅速增殖,数量大幅提高,同时发生分化,幼B淋巴细胞分化,形成能够分泌抗体的细胞

耶鲁公开课 - 生物医学工程探索课程节选